Release v0.1.16

Starting from cocotb v1.6 the use of <= syntax has been deprecated. This
commit replaces all use of this syntax with the ``.value =`` syntax.

README.md

@@ -32,7 +32,7 @@ See the `tests` directory, [verilog-axi](https://github.com/alexforencich/verilo
 
 ### AXI and AXI lite master
 
-The `AxiMaster` and `AxiLiteMaster` classes implement AXI masters and are capable of generating read and write operations against AXI slaves.  Requested operations will be split and aligned according to the AXI specification.  The `AxiMaster` module is capable of generating narrow bursts, handling multiple in-flight operations, and handling reordering and interleaving in responses across different transaction IDs.
+The `AxiMaster` and `AxiLiteMaster` classes implement AXI masters and are capable of generating read and write operations against AXI slaves.  Requested operations will be split and aligned according to the AXI specification.  The `AxiMaster` module is capable of generating narrow bursts, handling multiple in-flight operations, and handling reordering and interleaving in responses across different transaction IDs.  `AxiMaster` and `AxiLiteMaster` and related objects all extend `Region`, so they can be attached to `AddressSpace` objects to handle memory operations in the specified region.
 
 The `AxiMaster` is a wrapper around `AxiMasterWrite` and `AxiMasterRead`.  Similarly, `AxiLiteMaster` is a wrapper around `AxiLiteMasterWrite` and `AxiLiteMasterRead`.  If a read-only or write-only interface is required instead of a full interface, use the corresponding read-only or write-only variant, the usage and API are exactly the same.
 
@@ -42,36 +42,27 @@ To use these modules, import the one you need and connect it to the DUT:
 
     axi_master = AxiMaster(AxiBus.from_prefix(dut, "s_axi"), dut.clk, dut.rst)
 
-The first argument to the constructor accepts an `AxiBus` or `AxiLiteBus` object.  These objects are containers for the interface signals and include class methods to automate connections.
+The first argument to the constructor accepts an `AxiBus` or `AxiLiteBus` object, as appropriate.  These objects are containers for the interface signals and include class methods to automate connections.
 
-Once the module is instantiated, read and write operations can be initiated in a few different ways.
+Once the module is instantiated, read and write operations can be initiated in a couple of different ways.
 
-First, non-blocking operations can be started with `init_read()` and `init_write()`.  These methods will queue up a read or write operation to be carried out over the interface.  The result of the operation can be retrieved with `get_read_data()` and `get_write_resp()`.  To monitor the status of the module, `idle()`, `wait()`, `wait_read()`, and `wait_write()` can be used.  For example:
-
-    axi_master.init_write(0x0000, b'test')
-    await axi_master.wait()
-    resp = axi_master.get_write_resp()
-    axi_master.init_read(0x0000, 4)
-    await axi_master.wait()
-    data = axi_master.get_read_data()
-
-Alternatively, an event object can be provided as an argument to `init_read()` and `init_write()`, and the result can be retrieved from `Event.data`.  For example:
-
-    event = Event()
-    axi_master.init_write(0x0000, b'test', event=event)
-    await event.wait()
-    resp = event.data
-    event = Event()
-    axi_master.init_read(0x0000, 4, event=event)
-    await event.wait()
-    resp = event.data
-
-Second, blocking operations can be carried out with `read()` and `write()` and their associated word-access wrappers.  Multiple concurrent operations started from different coroutines are handled correctly.  For example:
+First, operations can be carried out with async blocking `read()`, `write()`, and their associated word-access wrappers.  Multiple concurrent operations started from different coroutines are handled correctly, with results returned in the order that the operations complete.  For example:
 
     await axi_master.write(0x0000, b'test')
     data = await axi_master.read(0x0000, 4)
 
-`read()`, `write()`, `get_read_data()`, and `get_write_resp()` return `namedtuple` objects containing _address_, _data_ or _length_, and _resp_.
+Additional parameters can be specified to control sideband signals and burst settings.  The transfer will be split into one or more bursts according to the AXI specification.  All bursts generated from the same call to `read()` or `write()` will use the same ID, which will be automatically generated if not specified.  `read()` and `write()` return `namedtuple` objects containing _address_, _data_ or _length_, and _resp_.  This is the preferred style, and this is the only style supported by the word-access wrappers.
+
+Alternatively, operations can be initiated with non-blocking `init_read()` and `init_write()`.  These functions return `Event` objects which are triggered when the operation completes, and the result can be retrieved from `Event.data`.  For example:
+
+    write_op = axi_master.init_write(0x0000, b'test')
+    await write_op.wait()
+    resp = write_op.data
+    read_op = axi_master.init_read(0x0000, 4)
+    await read_op.wait()
+    resp = read_op.data
+
+With this method, it is possible to start multiple concurrent operations from the same coroutine.  It is also possible to use the events with `Combine`, `First`, and `with_timeout`.
 
 #### `AxiMaster` and `AxiLiteMaster` constructor parameters
 
@@ -86,16 +77,12 @@ Second, blocking operations can be carried out with `read()` and `write()` and t
 
 #### Methods
 
-* `init_read(address, length, ...)`: initiate reading _length_ bytes, starting at _address_
-* `init_write(address, data, ...)`: initiate writing _data_ (bytes), starting from _address_
+* `init_read(address, length, ...)`: initiate reading _length_ bytes, starting at _address_.  Returns an `Event` object.
+* `init_write(address, data, ...)`: initiate writing _data_ (bytes), starting from _address_.  Returns an `Event` object.
 * `idle()`: returns _True_ when there are no outstanding operations in progress
 * `wait()`: blocking wait until all outstanding operations complete
 * `wait_read()`: wait until all outstanding read operations complete
 * `wait_write()`: wait until all outstanding write operations complete
-* `read_data_ready()`: determine if any read read data is available
-* `get_read_data()`: fetch first available read data
-* `write_resp_ready()`: determine if any write response is available
-* `get_write_resp()`: fetch first available write response
 * `read(address, length, ...)`: read _length_ bytes, starting at _address_
 * `read_words(address, count, byteorder='little', ws=2, ...)`: read _count_ _ws_-byte words, starting at _address_
 * `read_dwords(address, count, byteorder='little', ...)`: read _count_ 4-byte dwords, starting at _address_
@@ -125,20 +112,50 @@ Second, blocking operations can be carried out with `read()` and `write()` and t
 * _region_: AXI region field, default `0`
 * _user_: AXI user signal (awuser/aruser), default `0`
 * _wuser_: AXI wuser signal, default `0` (write-related methods only)
-* _event_: `Event` object used to wait on and retrieve result for specific operation, default `None` (`init_read()` and `init_write()` only).  If provided, the event will be triggered when the operation completes and the result returned via `Event.data` instead of `get_read_data()` or `get_write_resp()`.
+* _event_: `Event` object used to wait on and retrieve result for specific operation, default `None`.  The event will be triggered when the operation completes and the result returned via `Event.data`.  (`init_read()` and `init_write()` only)
 
 #### Additional optional arguments for `AxiLiteMaster`
 
 * _prot_: AXI protection flags, default `AxiProt.NONSECURE`
-* _event_: `Event` object used to wait on and retrieve result for specific operation, default `None` (`init_read()` and `init_write()` only).  If provided, the event will be triggered when the operation completes and the result returned via `Event.data` instead of `get_read_data()` or `get_write_resp()`.
+* _event_: `Event` object used to wait on and retrieve result for specific operation, default `None`.  The event will be triggered when the operation completes and the result returned via `Event.data`.  (`init_read()` and `init_write()` only)
 
 #### `AxiBus` and `AxiLiteBus` objects
 
-The `AxiBus`, `AxiLiteBus`, and related objects are containers for the interface signals.  These hold instances of bus objects for the individual channels, which are extensions of `cocotb.bus.Bus`.  Class methods `from_entity` and `from_prefix` are provided to facilitate signal name matching.  For AXI interfaces use `AxiBus`, `AxiReadBus`, or `AxiWriteBus`, as appropriate.  For AXI lite interfaces, use `AxiLiteBus`, `AxiLiteReadBus`, or `AxiLiteWriteBus`, as appropriate.
+The `AxiBus`, `AxiLiteBus`, and related objects are containers for the interface signals.  These hold instances of bus objects for the individual channels, which are currently extensions of `cocotb_bus.bus.Bus`.  Class methods `from_entity` and `from_prefix` are provided to facilitate signal name matching.  For AXI interfaces use `AxiBus`, `AxiReadBus`, or `AxiWriteBus`, as appropriate.  For AXI lite interfaces, use `AxiLiteBus`, `AxiLiteReadBus`, or `AxiLiteWriteBus`, as appropriate.
+
+### AXI and AXI lite slave
+
+The `AxiSlave` and `AxiLiteSlave` classes implement AXI slaves and are capable of completing read and write operations from upstream AXI masters.  The `AxiSlave` module is capable of handling narrow bursts.  These modules can either be used to perform memory reads and writes on a `MemoryInterface` on behalf of the DUT, or they can be extended to implement customized functionality.
+
+The `AxiSlave` is a wrapper around `AxiSlaveWrite` and `AxiSlaveRead`.  Similarly, `AxiLiteSlave` is a wrapper around `AxiLiteSlaveWrite` and `AxiLiteSlaveRead`.  If a read-only or write-only interface is required instead of a full interface, use the corresponding read-only or write-only variant, the usage and API are exactly the same.
+
+To use these modules, import the one you need and connect it to the DUT:
+
+    from cocotbext.axi import AxiBus, AxiSlave, MemoryRegion
+
+    axi_slave = AxiSlave(AxiBus.from_prefix(dut, "m_axi"), dut.clk, dut.rst)
+    region = MemoryRegion(2**axi_slave.read_if.address_width)
+    axi_slave.target = region
+
+The first argument to the constructor accepts an `AxiBus` or `AxiLiteBus` object.  These objects are containers for the interface signals and include class methods to automate connections.
+
+It is also possible to extend these modules; operation can be customized by overriding the internal `_read()` and `_write()` methods.  See `AxiRam` and `AxiLiteRam` for an example.
+
+#### `AxiSlave` and `AxiLiteSlave` constructor parameters
+
+* _bus_: `AxiBus` or `AxiLiteBus` object containing AXI interface signals
+* _clock_: clock signal
+* _reset_: reset signal (optional)
+* _reset_active_level_: reset active level (optional, default `True`)
+* _target_: target region (optional, default `None`)
+
+#### Attributes:
+
+* _target_: target region
 
 ### AXI and AXI lite RAM
 
-The `AxiRam` and `AxiLiteRam` classes implement AXI RAMs and are capable of completing read and write operations from upstream AXI masters.  The `AxiRam` module is capable of handling narrow bursts.
+The `AxiRam` and `AxiLiteRam` classes implement AXI RAMs and are capable of completing read and write operations from upstream AXI masters.  The `AxiRam` module is capable of handling narrow bursts.  These modules are extensions of the corresponding `AxiSlave` and `AxiLiteSlave` modules.
 
 The `AxiRam` is a wrapper around `AxiRamWrite` and `AxiRamRead`.  Similarly, `AxiLiteRam` is a wrapper around `AxiLiteRamWrite` and `AxiLiteRamRead`.  If a read-only or write-only interface is required instead of a full interface, use the corresponding read-only or write-only variant, the usage and API are exactly the same.
 
@@ -154,6 +171,7 @@ Once the module is instantiated, the memory contents can be accessed in a couple
 
     axi_ram.write(0x0000, b'test')
     data = axi_ram.read(0x0000, 4)
+    axi_ram.hexdump(0x0000, 4, prefix="RAM")
 
 Multi-port memories can be constructed by passing the `mem` object of the first instance to the other instances.  For example, here is how to create a four-port RAM:
 
@@ -255,8 +273,8 @@ Note: _byte_size_, _byte_lanes_, `len(tdata)`, and `len(tkeep)` are all related,
 * _pause_: stall the interface (deassert `tready` or `tvalid`) (source/sink only)
 * _queue_occupancy_bytes_: number of bytes in queue (all)
 * _queue_occupancy_frames_: number of frames in queue (all)
-* _queue_occupancy_limit_bytes_: max number of bytes in queue allowed before tready deassert (sink only)
-* _queue_occupancy_limit_frames_: max number of frames in queue allowed before tready deassert (sink only)
+* _queue_occupancy_limit_bytes_: max number of bytes in queue allowed before backpressure is applied (source/sink only)
+* _queue_occupancy_limit_frames_: max number of frames in queue allowed before backpressure is applied (source/sink only)
 
 #### Methods
 
@@ -270,7 +288,7 @@ Note: _byte_size_, _byte_lanes_, `len(tdata)`, and `len(tkeep)` are all related,
 * `read_nowait(count)`: read _count_ bytes from buffer (non-blocking) (sink/monitor)
 * `count()`: returns the number of items in the queue (all)
 * `empty()`: returns _True_ if the queue is empty (all)
-* `full()`: returns _True_ if the queue occupancy limits are met (sink)
+* `full()`: returns _True_ if the queue occupancy limits are met (source/sink)
 * `idle()`: returns _True_ if no transfer is in progress (all) or if the queue is not empty (source)
 * `clear()`: drop all data in queue (all)
 * `wait()`: wait for idle (source)
@@ -302,6 +320,66 @@ Methods:
 * `normalize()`: pack `tkeep`, `tid`, `tdest`, and `tuser` to the same length as `tdata`, replicating last element if necessary, initialize `tkeep` to list of `1` and `tid`, `tdest`, and `tuser` to list of `0` if not specified.
 * `compact()`: remove `tdata`, `tid`, `tdest`, and `tuser` values based on `tkeep`, remove `tkeep`, compact `tid`, `tdest`, and `tuser` to an int if all values are identical.
 
+### Address space abstraction
+
+The address space abstraction provides a framework for cross-connecting multiple memory-mapped interfaces for testing components that interface with complex systems, including components with DMA engines.
+
+`MemoryInterface` is the base class for all components in the address space abstraction.  `MemoryInterface` provides the core `read()` and `write()` methods, which implement bounds checking, as well as word-access wrappers.  Methods for creating `Window` and `WindowPool` objects are also provided.  The function `get_absolute_address()` translates addresses to the system address space.  `MemoryInterface` can be extended to implement custom functionality by overriding `_read()` and `_write()`.
+
+`Window` objects represent views onto a parent address space with some length and offset.  `read()` and `write()` operations on a `Window` are translated to the equivalent operations on the parent address space.  Multiple `Window` instances can overlap and access the same portion of address space.
+
+`WindowPool` provides a method for dynamically allocating windows from a section of address space.  It uses a standard memory management algorithm to provide naturally-aligned `Window` objects of the requested size.
+
+`Region` is the base class for all components which implement a portion of address space.  `Region` objects can be registered with `AddressSpace` objects to handle `read()` and `write()` operations in a specified region.  `Region` can be extended by components that implement a portion of address space.
+
+`MemoryRegion` is an extension of `Region` that uses an `mmap` instance to handle memory operations.  `MemoryRegion` also provides hex dump methods as well as indexing and slicing.
+
+`PeripheralRegion` is an extension of `Region` that can wrap another object that implements `read()` and `write()`, as an alternative to extending `Region`.
+
+`AddressSpace` is the core object for handling address spaces.  `Region` objects can be registered with `AddressSpace` with specified base address, size, and offset.  The `AddressSpace` object will then direct `read()` and `write()` operations to the appropriate `Region`s, splitting requests appropriately when necessary and translating addresses.  Regions registered with `offset` other than `None` are translated such that accesses to base address + N map to N + offset.  Regions registered with an `offset` of `None` are not translated.  `Region` objects registered with the same `AddressSpace` cannot overlap, however the same `Region` can be registered multiple times.  `AddressSpace` also provides a method for creating `Pool` objects.
+
+`Pool` is an extension of `AddressSpace` that supports dynamic allocation of `MemoryRegion`s.  It uses a standard memory management algorithm to provide naturally-aligned `MemoryRegion` objects of the requested size.
+
+#### Example
+
+This is a simple example that shows how the address space abstraction components can be used to connect a DUT to a simulated host system, including simulated RAM, an AXI interface from the DUT for DMA, and an AXI lite interface to the DUT for control.
+
+    from cocotbext.axi import AddressSpace, MemoryRegion
+    from cocotbext.axi import AxiBus, AxiLiteMaster, AxiSlave
+
+    # system address space
+    address_space = AddressSpace(2**32)
+
+    # RAM
+    ram = MemoryRegion(2**24)
+    address_space.register_region(ram, 0x0000_0000)
+    ram_pool = address_space.create_window_pool(0x0000_0000, 2**20)
+
+    # DUT control register interface
+    axil_master = AxiLiteMaster(AxiLiteBus.from_prefix(dut, "s_axil_ctrl"), dut.clk, dut.rst)
+    address_space.register_region(axil_master, 0x8000_0000)
+    ctrl_regs = address_space.create_window(0x8000_0000, axil_master.size)
+
+    # DMA from DUT
+    axi_slave = AxiSlave(AxiBus.from_prefix(dut, "m_axi_dma"), dut.clk, dut.rst, target=address_space)
+
+    # exercise DUT DMA functionality
+    src_block = ram_pool.alloc_window(1024)
+    dst_block = ram_pool.alloc_window(1024)
+
+    test_data = b'test data'
+    await src_block.write(0, test_data)
+
+    await ctrl_regs.write_dword(DMA_SRC_ADDR, src_block.get_absolute_address(0))
+    await ctrl_regs.write_dword(DMA_DST_ADDR, dst_block.get_absolute_address(0))
+    await ctrl_regs.write_dword(DMA_LEN, len(test_data))
+    await ctrl_regs.write_dword(DMA_CONTROL, 1)
+
+    while await ctrl_regs.read_dword(DMA_STATUS) == 0:
+        pass
+
+    assert await dst_block.read(0, len(test_data)) == test_data
+
 ### AXI signals
 
 * Write address channel

cocotbext/axi/__init__.py

@@ -26,14 +26,20 @@ from .version import __version__
 
 from .constants import AxiBurstType, AxiBurstSize, AxiLockType, AxiCacheBit, AxiProt, AxiResp
 
+from .address_space import MemoryInterface, Window, WindowPool
+from .address_space import Region, MemoryRegion, PeripheralRegion
+from .address_space import AddressSpace, Pool
+
 from .axis import AxiStreamFrame, AxiStreamBus, AxiStreamSource, AxiStreamSink, AxiStreamMonitor
 
 from .axil_channels import AxiLiteAWBus, AxiLiteWBus, AxiLiteBBus, AxiLiteARBus, AxiLiteRBus
 from .axil_channels import AxiLiteWriteBus, AxiLiteReadBus, AxiLiteBus
 from .axil_master import AxiLiteMasterWrite, AxiLiteMasterRead, AxiLiteMaster
+from .axil_slave import AxiLiteSlaveWrite, AxiLiteSlaveRead, AxiLiteSlave
 from .axil_ram import AxiLiteRamWrite, AxiLiteRamRead, AxiLiteRam
 
 from .axi_channels import AxiAWBus, AxiWBus, AxiBBus, AxiARBus, AxiRBus
 from .axi_channels import AxiWriteBus, AxiReadBus, AxiBus
 from .axi_master import AxiMasterWrite, AxiMasterRead, AxiMaster
+from .axi_slave import AxiSlaveWrite, AxiSlaveRead, AxiSlave
 from .axi_ram import AxiRamWrite, AxiRamRead, AxiRam

cocotbext/axi/address_space.py

@@ -0,0 +1,320 @@
+"""
+
+Copyright (c) 2021 Alex Forencich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+"""
+
+import mmap
+
+from .buddy_allocator import BuddyAllocator
+from .utils import hexdump, hexdump_lines, hexdump_str
+
+
+class MemoryInterface:
+    def __init__(self, size, base=0, parent=None, **kwargs):
+        self._parent = parent
+        self._size = size
+        self._base = base
+        super().__init__(**kwargs)
+
+    @property
+    def parent(self):
+        return self._parent
+
+    @property
+    def size(self):
+        return self._size
+
+    @property
+    def base(self):
+        return self._base
+
+    def check_range(self, address, length=0):
+        if address < 0 or address >= self.size:
+            raise ValueError("address out of range")
+        if length < 0:
+            raise ValueError("invalid length")
+        if address+length > self.size:
+            raise ValueError("operation out of range")
+
+    def get_absolute_address(self, address):
+        if self.base is None:
+            return None
+        self.check_range(address)
+        return address+self.base
+
+    async def _read(self, address, length, **kwargs):
+        raise NotImplementedError()
+
+    async def read(self, address, length, **kwargs):
+        self.check_range(address, length)
+        return await self._read(address, length, **kwargs)
+
+    async def read_words(self, address, count, byteorder='little', ws=2, **kwargs):
+        data = bytes(await self.read(address, count*ws, **kwargs))
+        words = []
+        for k in range(count):
+            words.append(int.from_bytes(data[ws*k:ws*(k+1)], byteorder))
+        return words
+
+    async def read_dwords(self, address, count, byteorder='little', **kwargs):
+        return await self.read_words(address, count, byteorder, 4, **kwargs)
+
+    async def read_qwords(self, address, count, byteorder='little', **kwargs):
+        return await self.read_words(address, count, byteorder, 8, **kwargs)
+
+    async def read_byte(self, address, **kwargs):
+        return (await self.read(address, 1, **kwargs)).data[0]
+
+    async def read_word(self, address, byteorder='little', ws=2, **kwargs):
+        return (await self.read_words(address, 1, byteorder, ws, **kwargs))[0]
+
+    async def read_dword(self, address, byteorder='little', **kwargs):
+        return (await self.read_dwords(address, 1, byteorder, **kwargs))[0]
+
+    async def read_qword(self, address, byteorder='little', **kwargs):
+        return (await self.read_qwords(address, 1, byteorder, **kwargs))[0]
+
+    async def _write(self, address, data, **kwargs):
+        raise NotImplementedError()
+
+    async def write(self, address, data, **kwargs):
+        self.check_range(address, len(data))
+        await self._write(address, data, **kwargs)
+
+    async def write_words(self, address, data, byteorder='little', ws=2, **kwargs):
+        words = data
+        data = bytearray()
+        for w in words:
+            data.extend(w.to_bytes(ws, byteorder))
+        await self.write(address, data, **kwargs)
+
+    async def write_dwords(self, address, data, byteorder='little', **kwargs):
+        await self.write_words(address, data, byteorder, 4, **kwargs)
+
+    async def write_qwords(self, address, data, byteorder='little', **kwargs):
+        await self.write_words(address, data, byteorder, 8, **kwargs)
+
+    async def write_byte(self, address, data, **kwargs):
+        await self.write(address, [data], **kwargs)
+
+    async def write_word(self, address, data, byteorder='little', ws=2, **kwargs):
+        await self.write_words(address, [data], byteorder, ws, **kwargs)
+
+    async def write_dword(self, address, data, byteorder='little', **kwargs):
+        await self.write_dwords(address, [data], byteorder, **kwargs)
+
+    async def write_qword(self, address, data, byteorder='little', **kwargs):
+        await self.write_qwords(address, [data], byteorder, **kwargs)
+
+    def create_window(self, offset, size):
+        self.check_range(offset, size)
+        return Window(self, offset, size, base=self.get_absolute_address(offset))
+
+    def create_window_pool(self, offset=None, size=None):
+        if offset is None:
+            offset = 0
+        if size is None:
+            size = self.size - offset
+        self.check_range(offset, size)
+        return WindowPool(self, offset, size, base=self.get_absolute_address(offset))
+
+    def __len__(self):
+        return self._size
+
+
+class Window(MemoryInterface):
+    def __init__(self, parent, offset, size, base=0, **kwargs):
+        super().__init__(size, base=base, parent=parent, **kwargs)
+        self._offset = offset
+
+    @property
+    def offset(self):
+        return self._offset
+
+    def get_parent_address(self, address):
+        if address < 0 or address >= self.size:
+            raise ValueError("address out of range")
+        return address+self.offset
+
+    async def _read(self, address, length, **kwargs):
+        return await self.parent.read(self.get_parent_address(address), length, **kwargs)
+
+    async def _write(self, address, data, **kwargs):
+        await self.parent.write(self.get_parent_address(address), data, **kwargs)
+
+
+class WindowPool(Window):
+    def __init__(self, parent, offset, size, base=None, **kwargs):
+        super().__init__(parent, offset, size, base=base, **kwargs)
+        self.allocator = BuddyAllocator(size)
+
+    def alloc_window(self, size):
+        return self.create_window(self.allocator.alloc(size), size)
+
+
+class Region(MemoryInterface):
+    def __init__(self, size, **kwargs):
+        super().__init__(size, **kwargs)
+
+
+class MemoryRegion(Region):
+    def __init__(self, size=4096, mem=None, **kwargs):
+        super().__init__(size, **kwargs)
+        if mem is None:
+            mem = mmap.mmap(-1, size)
+        self.mem = mem
+
+    async def _read(self, address, length, **kwargs):
+        return self.mem[address:address+length]
+
+    async def _write(self, address, data, **kwargs):
+        self.mem[address:address+len(data)] = data
+
+    def hexdump(self, address, length, prefix=""):
+        hexdump(self.mem[address:address+length], prefix=prefix, offset=address)
+
+    def hexdump_lines(self, address, length, prefix=""):
+        return hexdump_lines(self.mem[address:address+length], prefix=prefix, offset=address)
+
+    def hexdump_str(self, address, length, prefix=""):
+        return hexdump_str(self.mem[address:address+length], prefix=prefix, offset=address)
+
+    def __getitem__(self, key):
+        return self.mem[key]
+
+    def __setitem__(self, key, value):
+        self.mem[key] = value
+
+    def __bytes__(self):
+        return bytes(self.mem)
+
+
+class PeripheralRegion(Region):
+    def __init__(self, obj, size, **kwargs):
+        super().__init__(size, **kwargs)
+        self.obj = obj
+
+    async def _read(self, address, length, **kwargs):
+        try:
+            return await self.obj.read(address, length, **kwargs)
+        except TypeError:
+            return self.obj.read(address, length, **kwargs)
+
+    async def _write(self, address, data, **kwargs):
+        try:
+            await self.obj.write(address, data, **kwargs)
+        except TypeError:
+            self.obj.write(address, data, **kwargs)
+
+
+class AddressSpace(Region):
+    def __init__(self, size=2**64, base=0, parent=None, **kwargs):
+        super().__init__(size=size, base=base, parent=parent, **kwargs)
+        self.regions = []
+
+    def find_regions(self, address, length=1):
+        regions = []
+        if address < 0 or address >= self.size:
+            raise ValueError("address out of range")
+        if length < 0:
+            raise ValueError("invalid length")
+        length = max(length, 1)
+        for (base, size, translate, region) in self.regions:
+            if address < base+size and base < address+length:
+                regions.append((base, size, translate, region))
+        regions.sort()
+        return regions
+
+    def register_region(self, region, base, size=None, offset=0):
+        if size is None:
+            size = region.size
+        if self.find_regions(base, size):
+            raise ValueError("overlaps existing region")
+        region._parent = self
+        if offset == 0:
+            region._base = self.get_absolute_address(base)
+        else:
+            region._base = None
+        self.regions.append((base, size, offset, region))
+
+    async def read(self, address, length, **kwargs):
+        regions = self.find_regions(address, length)
+        data = bytearray()
+        if not regions:
+            raise Exception("Invalid address")
+        for base, size, offset, region in regions:
+            if base > address:
+                raise Exception("Invalid address")
+            seg_addr = address - base
+            seg_len = min(size-seg_addr, length)
+            if offset is None:
+                seg_addr = address
+                offset = 0
+            data.extend(bytes(await region.read(seg_addr+offset, seg_len, **kwargs)))
+            address += seg_len
+            length -= seg_len
+        if length > 0:
+            raise Exception("Invalid address")
+        return bytes(data)
+
+    async def write(self, address, data, **kwargs):
+        start = 0
+        length = len(data)
+        regions = self.find_regions(address, length)
+        if not regions:
+            raise Exception("Invalid address")
+        for base, size, offset, region in regions:
+            if base > address:
+                raise Exception("Invalid address")
+            seg_addr = address - base
+            seg_len = min(size-seg_addr, length)
+            if offset is None:
+                seg_addr = address
+                offset = 0
+            await region.write(seg_addr+offset, data[start:start+seg_len], **kwargs)
+            address += seg_len
+            start += seg_len
+            length -= seg_len
+        if length > 0:
+            raise Exception("Invalid address")
+
+    def create_pool(self, base=None, size=None):
+        if base is None:
+            base = 0
+        if size is None:
+            size = self.size - base
+        self.check_range(base, size)
+        pool = Pool(self, base, size)
+        self.register_region(pool, base, size)
+        return pool
+
+
+class Pool(AddressSpace):
+    def __init__(self, parent, base, size, **kwargs):
+        super().__init__(parent=parent, base=base, size=size, **kwargs)
+        self.allocator = BuddyAllocator(size)
+
+    def alloc_region(self, size):
+        base = self.allocator.alloc(size)
+        region = MemoryRegion(size)
+        self.register_region(region, base)
+        return region

cocotbext/axi/axi_channels.py

@@ -26,8 +26,8 @@ from .stream import define_stream
 
 # Write address channel
 AxiAWBus, AxiAWTransaction, AxiAWSource, AxiAWSink, AxiAWMonitor = define_stream("AxiAW",
-    signals=["awid", "awaddr", "awlen", "awsize", "awburst", "awprot", "awvalid", "awready"],
-    optional_signals=["awlock", "awcache", "awqos", "awregion", "awuser"],
+    signals=["awid", "awaddr", "awlen", "awsize", "awburst", "awvalid", "awready"],
+    optional_signals=["awlock", "awcache", "awprot", "awqos", "awregion", "awuser"],
     signal_widths={"awlen": 8, "awsize": 3, "awburst": 2, "awlock": 1,
         "awcache": 4, "awprot": 3, "awqos": 4, "awregion": 4}
 )
@@ -41,23 +41,23 @@ AxiWBus, AxiWTransaction, AxiWSource, AxiWSink, AxiWMonitor = define_stream("Axi
 
 # Write response channel
 AxiBBus, AxiBTransaction, AxiBSource, AxiBSink, AxiBMonitor = define_stream("AxiB",
-    signals=["bid", "bresp", "bvalid", "bready"],
-    optional_signals=["buser"],
+    signals=["bid", "bvalid", "bready"],
+    optional_signals=["bresp", "buser"],
     signal_widths={"bresp": 2}
 )
 
 # Read address channel
 AxiARBus, AxiARTransaction, AxiARSource, AxiARSink, AxiARMonitor = define_stream("AxiAR",
-    signals=["arid", "araddr", "arlen", "arsize", "arburst", "arprot", "arvalid", "arready"],
-    optional_signals=["arlock", "arcache", "arqos", "arregion", "aruser"],
+    signals=["arid", "araddr", "arlen", "arsize", "arburst", "arvalid", "arready"],
+    optional_signals=["arlock", "arcache", "arprot", "arqos", "arregion", "aruser"],
     signal_widths={"arlen": 8, "arsize": 3, "arburst": 2, "arlock": 1,
         "arcache": 4, "arprot": 3, "arqos": 4, "arregion": 4}
 )
 
 # Read data channel
 AxiRBus, AxiRTransaction, AxiRSource, AxiRSink, AxiRMonitor = define_stream("AxiR",
-    signals=["rid", "rdata", "rresp", "rlast", "rvalid", "rready"],
-    optional_signals=["ruser"],
+    signals=["rid", "rdata", "rlast", "rvalid", "rready"],
+    optional_signals=["rresp", "ruser"],
     signal_widths={"rresp": 2, "rlast": 1}
 )
 

cocotbext/axi/axi_ram.py

@@ -1,6 +1,6 @@
 """
 
-Copyright (c) 2020 Alex Forencich
+Copyright (c) 2021 Alex Forencich
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -22,251 +22,32 @@ THE SOFTWARE.
 
 """
 
-import logging
-
-import cocotb
-
-from .version import __version__
-from .constants import AxiBurstType, AxiProt, AxiResp
-from .axi_channels import AxiAWSink, AxiWSink, AxiBSource, AxiARSink, AxiRSource
+from .axi_slave import AxiSlaveWrite, AxiSlaveRead
 from .memory import Memory
-from .reset import Reset
 
 
-class AxiRamWrite(Memory, Reset):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, *args, **kwargs):
-        self.log = logging.getLogger(f"cocotb.{bus.aw._entity._name}.{bus.aw._name}")
+class AxiRamWrite(AxiSlaveWrite, Memory):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, **kwargs):
+        super().__init__(bus, clock, reset, reset_active_level=reset_active_level, size=size, mem=mem, **kwargs)
 
-        self.log.info("AXI RAM model (write)")
-        self.log.info("cocotbext-axi version %s", __version__)
-        self.log.info("Copyright (c) 2020 Alex Forencich")
-        self.log.info("https://github.com/alexforencich/cocotbext-axi")
+    async def _write(self, address, data):
+        self.write(address % self.size, data)
 
-        super().__init__(size, mem, *args, **kwargs)
 
-        self.aw_channel = AxiAWSink(bus.aw, clock, reset, reset_active_level)
-        self.w_channel = AxiWSink(bus.w, clock, reset, reset_active_level)
-        self.b_channel = AxiBSource(bus.b, clock, reset, reset_active_level)
+class AxiRamRead(AxiSlaveRead, Memory):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, **kwargs):
+        super().__init__(bus, clock, reset, reset_active_level=reset_active_level, size=size, mem=mem, **kwargs)
 
-        self.width = len(self.w_channel.bus.wdata)
-        self.byte_size = 8
-        self.byte_width = self.width // self.byte_size
-        self.strb_mask = 2**self.byte_width-1
-
-        self.log.info("AXI RAM model configuration:")
-        self.log.info("  Memory size: %d bytes", len(self.mem))
-        self.log.info("  Address width: %d bits", len(self.aw_channel.bus.awaddr))
-        self.log.info("  ID width: %d bits", len(self.aw_channel.bus.awid))
-        self.log.info("  Byte size: %d bits", self.byte_size)
-        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_width)
-
-        assert self.byte_width == len(self.w_channel.bus.wstrb)
-        assert self.byte_width * self.byte_size == self.width
-
-        assert len(self.b_channel.bus.bid) == len(self.aw_channel.bus.awid)
-
-        self._process_write_cr = None
-
-        self._init_reset(reset, reset_active_level)
-
-    def _handle_reset(self, state):
-        if state:
-            self.log.info("Reset asserted")
-            if self._process_write_cr is not None:
-                self._process_write_cr.kill()
-                self._process_write_cr = None
-        else:
-            self.log.info("Reset de-asserted")
-            if self._process_write_cr is None:
-                self._process_write_cr = cocotb.fork(self._process_write())
-
-        self.aw_channel.clear()
-        self.w_channel.clear()
-        self.b_channel.clear()
-
-    async def _process_write(self):
-        while True:
-            aw = await self.aw_channel.recv()
-
-            awid = int(aw.awid)
-            addr = int(aw.awaddr)
-            length = int(aw.awlen)
-            size = int(aw.awsize)
-            burst = int(aw.awburst)
-            prot = AxiProt(int(aw.awprot))
-
-            self.log.info("Write burst awid: 0x%x awaddr: 0x%08x awlen: %d awsize: %d awprot: %s",
-                awid, addr, length, size, prot)
-
-            num_bytes = 2**size
-            assert 0 < num_bytes <= self.byte_width
-
-            aligned_addr = (addr // num_bytes) * num_bytes
-            length += 1
-
-            transfer_size = num_bytes*length
-
-            if burst == AxiBurstType.WRAP:
-                lower_wrap_boundary = (addr // transfer_size) * transfer_size
-                upper_wrap_boundary = lower_wrap_boundary + transfer_size
-
-            if burst == AxiBurstType.INCR:
-                # check 4k boundary crossing
-                assert 0x1000-(aligned_addr & 0xfff) >= transfer_size
-
-            cur_addr = aligned_addr
-
-            for n in range(length):
-                cur_word_addr = (cur_addr // self.byte_width) * self.byte_width
-
-                w = await self.w_channel.recv()
-
-                data = int(w.wdata)
-                strb = int(w.wstrb)
-                last = int(w.wlast)
-
-                # todo latency
-
-                self.mem.seek(cur_word_addr % self.size)
-
-                data = data.to_bytes(self.byte_width, 'little')
-
-                self.log.debug("Write word awid: 0x%x addr: 0x%08x wstrb: 0x%02x data: %s",
-                    awid, cur_addr, strb, ' '.join((f'{c:02x}' for c in data)))
-
-                for i in range(self.byte_width):
-                    if strb & (1 << i):
-                        self.mem.write(data[i:i+1])
-                    else:
-                        self.mem.seek(1, 1)
-
-                assert last == (n == length-1)
-
-                if burst != AxiBurstType.FIXED:
-                    cur_addr += num_bytes
-
-                    if burst == AxiBurstType.WRAP:
-                        if cur_addr == upper_wrap_boundary:
-                            cur_addr = lower_wrap_boundary
-
-            b = self.b_channel._transaction_obj()
-            b.bid = awid
-            b.bresp = AxiResp.OKAY
-
-            await self.b_channel.send(b)
-
-
-class AxiRamRead(Memory, Reset):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, *args, **kwargs):
-        self.log = logging.getLogger(f"cocotb.{bus.ar._entity._name}.{bus.ar._name}")
-
-        self.log.info("AXI RAM model (read)")
-        self.log.info("cocotbext-axi version %s", __version__)
-        self.log.info("Copyright (c) 2020 Alex Forencich")
-        self.log.info("https://github.com/alexforencich/cocotbext-axi")
-
-        super().__init__(size, mem, *args, **kwargs)
-
-        self.ar_channel = AxiARSink(bus.ar, clock, reset, reset_active_level)
-        self.r_channel = AxiRSource(bus.r, clock, reset, reset_active_level)
-
-        self.width = len(self.r_channel.bus.rdata)
-        self.byte_size = 8
-        self.byte_width = self.width // self.byte_size
-
-        self.log.info("AXI RAM model configuration:")
-        self.log.info("  Memory size: %d bytes", len(self.mem))
-        self.log.info("  Address width: %d bits", len(self.ar_channel.bus.araddr))
-        self.log.info("  ID width: %d bits", len(self.ar_channel.bus.arid))
-        self.log.info("  Byte size: %d bits", self.byte_size)
-        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_width)
-
-        assert self.byte_width * self.byte_size == self.width
-
-        assert len(self.r_channel.bus.rid) == len(self.ar_channel.bus.arid)
-
-        self._process_read_cr = None
-
-        self._init_reset(reset, reset_active_level)
-
-    def _handle_reset(self, state):
-        if state:
-            self.log.info("Reset asserted")
-            if self._process_read_cr is not None:
-                self._process_read_cr.kill()
-                self._process_read_cr = None
-        else:
-            self.log.info("Reset de-asserted")
-            if self._process_read_cr is None:
-                self._process_read_cr = cocotb.fork(self._process_read())
-
-        self.ar_channel.clear()
-        self.r_channel.clear()
-
-    async def _process_read(self):
-        while True:
-            ar = await self.ar_channel.recv()
-
-            arid = int(ar.arid)
-            addr = int(ar.araddr)
-            length = int(ar.arlen)
-            size = int(ar.arsize)
-            burst = int(ar.arburst)
-            prot = AxiProt(ar.arprot)
-
-            self.log.info("Read burst arid: 0x%x araddr: 0x%08x arlen: %d arsize: %d arprot: %s",
-                arid, addr, length, size, prot)
-
-            num_bytes = 2**size
-            assert 0 < num_bytes <= self.byte_width
-
-            aligned_addr = (addr // num_bytes) * num_bytes
-            length += 1
-
-            transfer_size = num_bytes*length
-
-            if burst == AxiBurstType.WRAP:
-                lower_wrap_boundary = (addr // transfer_size) * transfer_size
-                upper_wrap_boundary = lower_wrap_boundary + transfer_size
-
-            if burst == AxiBurstType.INCR:
-                # check 4k boundary crossing
-                assert 0x1000-(aligned_addr & 0xfff) >= transfer_size
-
-            cur_addr = aligned_addr
-
-            for n in range(length):
-                cur_word_addr = (cur_addr // self.byte_width) * self.byte_width
-
-                self.mem.seek(cur_word_addr % self.size)
-
-                data = self.mem.read(self.byte_width)
-
-                r = self.r_channel._transaction_obj()
-                r.rid = arid
-                r.rdata = int.from_bytes(data, 'little')
-                r.rlast = n == length-1
-                r.rresp = AxiResp.OKAY
-
-                await self.r_channel.send(r)
-
-                self.log.debug("Read word awid: 0x%x addr: 0x%08x data: %s",
-                    arid, cur_addr, ' '.join((f'{c:02x}' for c in data)))
-
-                if burst != AxiBurstType.FIXED:
-                    cur_addr += num_bytes
-
-                    if burst == AxiBurstType.WRAP:
-                        if cur_addr == upper_wrap_boundary:
-                            cur_addr = lower_wrap_boundary
+    async def _read(self, address, length):
+        return self.read(address % self.size, length)
 
 
 class AxiRam(Memory):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, *args, **kwargs):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, **kwargs):
         self.write_if = None
         self.read_if = None
 
-        super().__init__(size, mem, *args, **kwargs)
+        super().__init__(size, mem, **kwargs)
 
         self.write_if = AxiRamWrite(bus.write, clock, reset, reset_active_level, mem=self.mem)
         self.read_if = AxiRamRead(bus.read, clock, reset, reset_active_level, mem=self.mem)

cocotbext/axi/axi_slave.py

@@ -0,0 +1,335 @@
+"""
+
+Copyright (c) 2021 Alex Forencich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+"""
+
+import logging
+
+import cocotb
+
+from .version import __version__
+from .constants import AxiBurstType, AxiProt, AxiResp
+from .axi_channels import AxiAWSink, AxiWSink, AxiBSource, AxiARSink, AxiRSource
+from .reset import Reset
+
+
+class AxiSlaveWrite(Reset):
+    def __init__(self, bus, clock, reset=None, target=None, reset_active_level=True, **kwargs):
+        self.bus = bus
+        self.clock = clock
+        self.reset = reset
+        self.target = target
+        self.log = logging.getLogger(f"cocotb.{bus.aw._entity._name}.{bus.aw._name}")
+
+        self.log.info("AXI slave model (write)")
+        self.log.info("cocotbext-axi version %s", __version__)
+        self.log.info("Copyright (c) 2021 Alex Forencich")
+        self.log.info("https://github.com/alexforencich/cocotbext-axi")
+
+        super().__init__(**kwargs)
+
+        self.aw_channel = AxiAWSink(bus.aw, clock, reset, reset_active_level)
+        self.aw_channel.queue_occupancy_limit = 2
+        self.w_channel = AxiWSink(bus.w, clock, reset, reset_active_level)
+        self.w_channel.queue_occupancy_limit = 2
+        self.b_channel = AxiBSource(bus.b, clock, reset, reset_active_level)
+        self.b_channel.queue_occupancy_limit = 2
+
+        self.address_width = len(self.aw_channel.bus.awaddr)
+        self.id_width = len(self.aw_channel.bus.awid)
+        self.width = len(self.w_channel.bus.wdata)
+        self.byte_size = 8
+        self.byte_lanes = self.width // self.byte_size
+        self.strb_mask = 2**self.byte_lanes-1
+
+        self.max_burst_size = (self.byte_lanes-1).bit_length()
+
+        self.log.info("AXI slave model configuration:")
+        self.log.info("  Address width: %d bits", self.address_width)
+        self.log.info("  ID width: %d bits", self.id_width)
+        self.log.info("  Byte size: %d bits", self.byte_size)
+        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_lanes)
+
+        self.log.info("AXI slave model signals:")
+        for bus in (self.bus.aw, self.bus.w, self.bus.b):
+            for sig in sorted(list(set().union(bus._signals, bus._optional_signals))):
+                if hasattr(bus, sig):
+                    self.log.info("  %s width: %d bits", sig, len(getattr(bus, sig)))
+                else:
+                    self.log.info("  %s: not present", sig)
+
+        assert self.byte_lanes == len(self.w_channel.bus.wstrb)
+        assert self.byte_lanes * self.byte_size == self.width
+
+        assert len(self.b_channel.bus.bid) == len(self.aw_channel.bus.awid)
+
+        self._process_write_cr = None
+
+        self._init_reset(reset, reset_active_level)
+
+    async def _write(self, address, data):
+        await self.target.write(address, data)
+
+    def _handle_reset(self, state):
+        if state:
+            self.log.info("Reset asserted")
+            if self._process_write_cr is not None:
+                self._process_write_cr.kill()
+                self._process_write_cr = None
+
+            self.aw_channel.clear()
+            self.w_channel.clear()
+            self.b_channel.clear()
+        else:
+            self.log.info("Reset de-asserted")
+            if self._process_write_cr is None:
+                self._process_write_cr = cocotb.fork(self._process_write())
+
+    async def _process_write(self):
+        while True:
+            aw = await self.aw_channel.recv()
+
+            awid = int(getattr(aw, 'awid', 0))
+            addr = int(aw.awaddr)
+            length = int(getattr(aw, 'awlen', 0))
+            size = int(getattr(aw, 'awsize', self.max_burst_size))
+            burst = AxiBurstType(getattr(aw, 'awburst', AxiBurstType.INCR))
+            prot = AxiProt(getattr(aw, 'awprot', AxiProt.NONSECURE))
+
+            self.log.info("Write burst awid: 0x%x awaddr: 0x%08x awlen: %d awsize: %d awprot: %s",
+                    awid, addr, length, size, prot)
+
+            num_bytes = 2**size
+            assert 0 < num_bytes <= self.byte_lanes
+
+            aligned_addr = (addr // num_bytes) * num_bytes
+            length += 1
+
+            transfer_size = num_bytes*length
+
+            if burst == AxiBurstType.WRAP:
+                lower_wrap_boundary = (addr // transfer_size) * transfer_size
+                upper_wrap_boundary = lower_wrap_boundary + transfer_size
+
+            if burst == AxiBurstType.INCR:
+                # check 4k boundary crossing
+                assert 0x1000-(aligned_addr & 0xfff) >= transfer_size
+
+            cur_addr = aligned_addr
+
+            b = self.b_channel._transaction_obj()
+            b.bid = awid
+            b.bresp = AxiResp.OKAY
+
+            for n in range(length):
+                cur_word_addr = (cur_addr // self.byte_lanes) * self.byte_lanes
+
+                w = await self.w_channel.recv()
+
+                data = int(w.wdata)
+                strb = int(getattr(w, 'wstrb', self.strb_mask))
+                last = int(w.wlast)
+
+                # generate operation list
+                offset = 0
+                start_offset = None
+                write_ops = []
+
+                data = data.to_bytes(self.byte_lanes, 'little')
+
+                if self.log.isEnabledFor(logging.DEBUG):
+                    self.log.debug("Write word awid: 0x%x addr: 0x%08x wstrb: 0x%02x data: %s",
+                            awid, cur_addr, strb, ' '.join((f'{c:02x}' for c in data)))
+
+                for i in range(self.byte_lanes):
+                    if strb & (1 << i):
+                        if start_offset is None:
+                            start_offset = offset
+                    else:
+                        if start_offset is not None and offset != start_offset:
+                            write_ops.append((cur_word_addr+start_offset, data[start_offset:offset]))
+                        start_offset = None
+
+                    offset += 1
+
+                if start_offset is not None and offset != start_offset:
+                    write_ops.append((cur_word_addr+start_offset, data[start_offset:offset]))
+
+                # perform writes
+                try:
+                    for addr, data in write_ops:
+                        await self._write(addr, data)
+                except Exception:
+                    self.log.warning("Write operation failed")
+                    b.bresp = AxiResp.SLVERR
+
+                assert last == (n == length-1)
+
+                if burst != AxiBurstType.FIXED:
+                    cur_addr += num_bytes
+
+                    if burst == AxiBurstType.WRAP:
+                        if cur_addr == upper_wrap_boundary:
+                            cur_addr = lower_wrap_boundary
+
+            await self.b_channel.send(b)
+
+
+class AxiSlaveRead(Reset):
+    def __init__(self, bus, clock, reset=None, target=None, reset_active_level=True, **kwargs):
+        self.bus = bus
+        self.clock = clock
+        self.reset = reset
+        self.target = target
+        self.log = logging.getLogger(f"cocotb.{bus.ar._entity._name}.{bus.ar._name}")
+
+        self.log.info("AXI slave model (read)")
+        self.log.info("cocotbext-axi version %s", __version__)
+        self.log.info("Copyright (c) 2021 Alex Forencich")
+        self.log.info("https://github.com/alexforencich/cocotbext-axi")
+
+        super().__init__(**kwargs)
+
+        self.ar_channel = AxiARSink(bus.ar, clock, reset, reset_active_level)
+        self.ar_channel.queue_occupancy_limit = 2
+        self.r_channel = AxiRSource(bus.r, clock, reset, reset_active_level)
+        self.r_channel.queue_occupancy_limit = 2
+
+        self.address_width = len(self.ar_channel.bus.araddr)
+        self.id_width = len(self.ar_channel.bus.arid)
+        self.width = len(self.r_channel.bus.rdata)
+        self.byte_size = 8
+        self.byte_lanes = self.width // self.byte_size
+
+        self.max_burst_size = (self.byte_lanes-1).bit_length()
+
+        self.log.info("AXI slave model configuration:")
+        self.log.info("  Address width: %d bits", self.address_width)
+        self.log.info("  ID width: %d bits", self.id_width)
+        self.log.info("  Byte size: %d bits", self.byte_size)
+        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_lanes)
+
+        self.log.info("AXI slave model signals:")
+        for bus in (self.bus.ar, self.bus.r):
+            for sig in sorted(list(set().union(bus._signals, bus._optional_signals))):
+                if hasattr(bus, sig):
+                    self.log.info("  %s width: %d bits", sig, len(getattr(bus, sig)))
+                else:
+                    self.log.info("  %s: not present", sig)
+
+        assert self.byte_lanes * self.byte_size == self.width
+
+        assert len(self.r_channel.bus.rid) == len(self.ar_channel.bus.arid)
+
+        self._process_read_cr = None
+
+        self._init_reset(reset, reset_active_level)
+
+    async def _read(self, address, length):
+        return await self.target.read(address, length)
+
+    def _handle_reset(self, state):
+        if state:
+            self.log.info("Reset asserted")
+            if self._process_read_cr is not None:
+                self._process_read_cr.kill()
+                self._process_read_cr = None
+
+            self.ar_channel.clear()
+            self.r_channel.clear()
+        else:
+            self.log.info("Reset de-asserted")
+            if self._process_read_cr is None:
+                self._process_read_cr = cocotb.fork(self._process_read())
+
+    async def _process_read(self):
+        while True:
+            ar = await self.ar_channel.recv()
+
+            arid = int(getattr(ar, 'arid', 0))
+            addr = int(ar.araddr)
+            length = int(getattr(ar, 'arlen', 0))
+            size = int(getattr(ar, 'arsize', self.max_burst_size))
+            burst = AxiBurstType(getattr(ar, 'arburst', AxiBurstType.INCR))
+            prot = AxiProt(getattr(ar, 'arprot', AxiProt.NONSECURE))
+
+            self.log.info("Read burst arid: 0x%x araddr: 0x%08x arlen: %d arsize: %d arprot: %s",
+                    arid, addr, length, size, prot)
+
+            num_bytes = 2**size
+            assert 0 < num_bytes <= self.byte_lanes
+
+            aligned_addr = (addr // num_bytes) * num_bytes
+            length += 1
+
+            transfer_size = num_bytes*length
+
+            if burst == AxiBurstType.WRAP:
+                lower_wrap_boundary = (addr // transfer_size) * transfer_size
+                upper_wrap_boundary = lower_wrap_boundary + transfer_size
+
+            if burst == AxiBurstType.INCR:
+                # check 4k boundary crossing
+                assert 0x1000-(aligned_addr & 0xfff) >= transfer_size
+
+            cur_addr = aligned_addr
+
+            for n in range(length):
+                cur_word_addr = (cur_addr // self.byte_lanes) * self.byte_lanes
+
+                r = self.r_channel._transaction_obj()
+                r.rid = arid
+                r.rlast = n == length-1
+                r.rresp = AxiResp.OKAY
+
+                try:
+                    data = await self._read(cur_word_addr, self.byte_lanes)
+                except Exception:
+                    self.log.warning("Read operation failed")
+                    data = bytes(self.byte_lanes)
+                    r.rresp = AxiResp.SLVERR
+
+                r.rdata = int.from_bytes(data, 'little')
+
+                await self.r_channel.send(r)
+
+                if self.log.isEnabledFor(logging.DEBUG):
+                    self.log.debug("Read word awid: 0x%x addr: 0x%08x data: %s",
+                            arid, cur_addr, ' '.join((f'{c:02x}' for c in data)))
+
+                if burst != AxiBurstType.FIXED:
+                    cur_addr += num_bytes
+
+                    if burst == AxiBurstType.WRAP:
+                        if cur_addr == upper_wrap_boundary:
+                            cur_addr = lower_wrap_boundary
+
+
+class AxiSlave:
+    def __init__(self, bus, clock, reset=None, target=None, reset_active_level=True, **kwargs):
+        self.write_if = None
+        self.read_if = None
+
+        super().__init__(**kwargs)
+
+        self.write_if = AxiSlaveWrite(bus.write, clock, reset, target, reset_active_level)
+        self.read_if = AxiSlaveRead(bus.read, clock, reset, target, reset_active_level)

cocotbext/axi/axil_channels.py

@@ -26,7 +26,8 @@ from .stream import define_stream
 
 # Write address channel
 AxiLiteAWBus, AxiLiteAWTransaction, AxiLiteAWSource, AxiLiteAWSink, AxiLiteAWMonitor = define_stream("AxiLiteAW",
-    signals=["awaddr", "awprot", "awvalid", "awready"],
+    signals=["awaddr", "awvalid", "awready"],
+    optional_signals=["awprot"],
     signal_widths={"awprot": 3}
 )
 
@@ -37,19 +38,22 @@ AxiLiteWBus, AxiLiteWTransaction, AxiLiteWSource, AxiLiteWSink, AxiLiteWMonitor
 
 # Write response channel
 AxiLiteBBus, AxiLiteBTransaction, AxiLiteBSource, AxiLiteBSink, AxiLiteBMonitor = define_stream("AxiLiteB",
-    signals=["bresp", "bvalid", "bready"],
+    signals=["bvalid", "bready"],
+    optional_signals=["bresp"],
     signal_widths={"bresp": 2}
 )
 
 # Read address channel
 AxiLiteARBus, AxiLiteARTransaction, AxiLiteARSource, AxiLiteARSink, AxiLiteARMonitor = define_stream("AxiLiteAR",
-    signals=["araddr", "arprot", "arvalid", "arready"],
+    signals=["araddr", "arvalid", "arready"],
+    optional_signals=["arprot"],
     signal_widths={"arprot": 3}
 )
 
 # Read data channel
 AxiLiteRBus, AxiLiteRTransaction, AxiLiteRSource, AxiLiteRSink, AxiLiteRMonitor = define_stream("AxiLiteR",
-    signals=["rdata", "rresp", "rvalid", "rready"],
+    signals=["rdata", "rvalid", "rready"],
+    optional_signals=["rresp"],
     signal_widths={"rresp": 2}
 )
 

cocotbext/axi/axil_master.py

@@ -23,29 +23,71 @@ THE SOFTWARE.
 """
 
 import logging
-from collections import deque, namedtuple
+from typing import NamedTuple
 
 import cocotb
+from cocotb.queue import Queue
 from cocotb.triggers import Event
 
 from .version import __version__
 from .constants import AxiProt, AxiResp
 from .axil_channels import AxiLiteAWSource, AxiLiteWSource, AxiLiteBSink, AxiLiteARSource, AxiLiteRSink
+from .address_space import Region
 from .reset import Reset
 
-# AXI lite master write
-AxiLiteWriteCmd = namedtuple("AxiLiteWriteCmd", ["address", "data", "prot", "event"])
-AxiLiteWriteRespCmd = namedtuple("AxiLiteWriteRespCmd", ["address", "length", "cycles", "prot", "event"])
-AxiLiteWriteResp = namedtuple("AxiLiteWriteResp", ["address", "length", "resp"])
 
-# AXI lite master read
-AxiLiteReadCmd = namedtuple("AxiLiteReadCmd", ["address", "length", "prot", "event"])
-AxiLiteReadRespCmd = namedtuple("AxiLiteReadRespCmd", ["address", "length", "cycles", "prot", "event"])
-AxiLiteReadResp = namedtuple("AxiLiteReadResp", ["address", "data", "resp"])
+# AXI lite master write helper objects
+class AxiLiteWriteCmd(NamedTuple):
+    address: int
+    data: bytes
+    prot: AxiProt
+    event: Event
 
 
-class AxiLiteMasterWrite(Reset):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True):
+class AxiLiteWriteRespCmd(NamedTuple):
+    address: int
+    length: int
+    cycles: int
+    prot: AxiProt
+    event: Event
+
+
+class AxiLiteWriteResp(NamedTuple):
+    address: int
+    length: int
+    resp: AxiResp
+
+
+# AXI lite master read helper objects
+class AxiLiteReadCmd(NamedTuple):
+    address: int
+    length: int
+    prot: AxiProt
+    event: Event
+
+
+class AxiLiteReadRespCmd(NamedTuple):
+    address: int
+    length: int
+    cycles: int
+    prot: AxiProt
+    event: Event
+
+
+class AxiLiteReadResp(NamedTuple):
+    address: int
+    data: bytes
+    resp: AxiResp
+
+    def __bytes__(self):
+        return self.data
+
+
+class AxiLiteMasterWrite(Region, Reset):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, **kwargs):
+        self.bus = bus
+        self.clock = clock
+        self.reset = reset
         self.log = logging.getLogger(f"cocotb.{bus.aw._entity._name}.{bus.aw._name}")
 
         self.log.info("AXI lite master (write)")
@@ -54,33 +96,47 @@ class AxiLiteMasterWrite(Reset):
         self.log.info("https://github.com/alexforencich/cocotbext-axi")
 
         self.aw_channel = AxiLiteAWSource(bus.aw, clock, reset, reset_active_level)
+        self.aw_channel.queue_occupancy_limit = 2
         self.w_channel = AxiLiteWSource(bus.w, clock, reset, reset_active_level)
+        self.w_channel.queue_occupancy_limit = 2
         self.b_channel = AxiLiteBSink(bus.b, clock, reset, reset_active_level)
+        self.b_channel.queue_occupancy_limit = 2
 
-        self.write_command_queue = deque()
-        self.write_command_sync = Event()
-        self.write_resp_queue = deque()
-        self.write_resp_sync = Event()
+        self.write_command_queue = Queue()
+        self.current_write_command = None
 
-        self.int_write_resp_command_queue = deque()
-        self.int_write_resp_command_sync = Event()
+        self.int_write_resp_command_queue = Queue()
+        self.current_write_resp_command = None
 
         self.in_flight_operations = 0
         self._idle = Event()
         self._idle.set()
 
+        self.address_width = len(self.aw_channel.bus.awaddr)
         self.width = len(self.w_channel.bus.wdata)
         self.byte_size = 8
-        self.byte_width = self.width // self.byte_size
-        self.strb_mask = 2**self.byte_width-1
+        self.byte_lanes = self.width // self.byte_size
+        self.strb_mask = 2**self.byte_lanes-1
+
+        self.awprot_present = hasattr(self.bus.aw, "awprot")
+
+        super().__init__(2**self.address_width, **kwargs)
 
         self.log.info("AXI lite master configuration:")
-        self.log.info("  Address width: %d bits", len(self.aw_channel.bus.awaddr))
+        self.log.info("  Address width: %d bits", self.address_width)
         self.log.info("  Byte size: %d bits", self.byte_size)
-        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_width)
+        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_lanes)
 
-        assert self.byte_width == len(self.w_channel.bus.wstrb)
-        assert self.byte_width * self.byte_size == self.width
+        self.log.info("AXI lite master signals:")
+        for bus in (self.bus.aw, self.bus.w, self.bus.b):
+            for sig in sorted(list(set().union(bus._signals, bus._optional_signals))):
+                if hasattr(bus, sig):
+                    self.log.info("  %s width: %d bits", sig, len(getattr(bus, sig)))
+                else:
+                    self.log.info("  %s: not present", sig)
+
+        assert self.byte_lanes == len(self.w_channel.bus.wstrb)
+        assert self.byte_lanes * self.byte_size == self.width
 
         self._process_write_cr = None
         self._process_write_resp_cr = None
@@ -88,14 +144,27 @@ class AxiLiteMasterWrite(Reset):
         self._init_reset(reset, reset_active_level)
 
     def init_write(self, address, data, prot=AxiProt.NONSECURE, event=None):
-        if event is not None and not isinstance(event, Event):
+        if event is None:
+            event = Event()
+
+        if not isinstance(event, Event):
             raise ValueError("Expected event object")
 
+        if address < 0 or address >= 2**self.address_width:
+            raise ValueError("Address out of range")
+
+        if isinstance(data, int):
+            raise ValueError("Expected bytes or bytearray for data")
+
+        if not self.awprot_present and prot != AxiProt.NONSECURE:
+            raise ValueError("awprot sideband signal value specified, but signal is not connected")
+
         self.in_flight_operations += 1
         self._idle.clear()
 
-        self.write_command_queue.append(AxiLiteWriteCmd(address, bytearray(data), prot, event))
-        self.write_command_sync.set()
+        self.write_command_queue.put_nowait(AxiLiteWriteCmd(address, bytes(data), prot, event))
+
+        return event
 
     def idle(self):
         return not self.in_flight_operations
@@ -104,45 +173,11 @@ class AxiLiteMasterWrite(Reset):
         while not self.idle():
             await self._idle.wait()
 
-    def write_resp_ready(self):
-        return bool(self.write_resp_queue)
-
-    def get_write_resp(self):
-        if self.write_resp_queue:
-            return self.write_resp_queue.popleft()
-        return None
-
     async def write(self, address, data, prot=AxiProt.NONSECURE):
-        event = Event()
-        self.init_write(address, data, prot, event)
+        event = self.init_write(address, data, prot)
         await event.wait()
         return event.data
 
-    async def write_words(self, address, data, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        words = data
-        data = bytearray()
-        for w in words:
-            data.extend(w.to_bytes(ws, byteorder))
-        await self.write(address, data, prot)
-
-    async def write_dwords(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        await self.write_words(address, data, byteorder, 4, prot)
-
-    async def write_qwords(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        await self.write_words(address, data, byteorder, 8, prot)
-
-    async def write_byte(self, address, data, prot=AxiProt.NONSECURE):
-        await self.write(address, [data], prot)
-
-    async def write_word(self, address, data, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        await self.write_words(address, [data], byteorder, ws, prot)
-
-    async def write_dword(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        await self.write_dwords(address, [data], byteorder, prot)
-
-    async def write_qword(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        await self.write_qwords(address, [data], byteorder, prot)
-
     def _handle_reset(self, state):
         if state:
             self.log.info("Reset asserted")
@@ -152,6 +187,36 @@ class AxiLiteMasterWrite(Reset):
             if self._process_write_resp_cr is not None:
                 self._process_write_resp_cr.kill()
                 self._process_write_resp_cr = None
+
+            self.aw_channel.clear()
+            self.w_channel.clear()
+            self.b_channel.clear()
+
+            def flush_cmd(cmd):
+                self.log.warning("Flushed write operation during reset: %s", cmd)
+                if cmd.event:
+                    cmd.event.set(None)
+
+            while not self.write_command_queue.empty():
+                cmd = self.write_command_queue.get_nowait()
+                flush_cmd(cmd)
+
+            if self.current_write_command:
+                cmd = self.current_write_command
+                self.current_write_command = None
+                flush_cmd(cmd)
+
+            while not self.int_write_resp_command_queue.empty():
+                cmd = self.int_write_resp_command_queue.get_nowait()
+                flush_cmd(cmd)
+
+            if self.current_write_resp_command:
+                cmd = self.current_write_resp_command
+                self.current_write_resp_command = None
+                flush_cmd(cmd)
+
+            self.in_flight_operations = 0
+            self._idle.set()
         else:
             self.log.info("Reset de-asserted")
             if self._process_write_cr is None:
@@ -159,55 +224,33 @@ class AxiLiteMasterWrite(Reset):
             if self._process_write_resp_cr is None:
                 self._process_write_resp_cr = cocotb.fork(self._process_write_resp())
 
-        self.aw_channel.clear()
-        self.w_channel.clear()
-        self.b_channel.clear()
-
-        while self.write_command_queue:
-            cmd = self.write_command_queue.popleft()
-            if cmd.event:
-                cmd.event.set(None)
-
-        while self.int_write_resp_command_queue:
-            cmd = self.int_write_resp_command_queue.popleft()
-            if cmd.event:
-                cmd.event.set(None)
-
-        self.write_resp_queue.clear()
-
-        self.in_flight_operations = 0
-        self._idle.set()
-
     async def _process_write(self):
         while True:
-            if not self.write_command_queue:
-                self.write_command_sync.clear()
-                await self.write_command_sync.wait()
+            cmd = await self.write_command_queue.get()
+            self.current_write_command = cmd
 
-            cmd = self.write_command_queue.popleft()
+            word_addr = (cmd.address // self.byte_lanes) * self.byte_lanes
 
-            word_addr = (cmd.address // self.byte_width) * self.byte_width
-
-            start_offset = cmd.address % self.byte_width
-            end_offset = ((cmd.address + len(cmd.data) - 1) % self.byte_width) + 1
+            start_offset = cmd.address % self.byte_lanes
+            end_offset = ((cmd.address + len(cmd.data) - 1) % self.byte_lanes) + 1
 
             strb_start = (self.strb_mask << start_offset) & self.strb_mask
-            strb_end = self.strb_mask >> (self.byte_width - end_offset)
+            strb_end = self.strb_mask >> (self.byte_lanes - end_offset)
 
-            cycles = (len(cmd.data) + (cmd.address % self.byte_width) + self.byte_width-1) // self.byte_width
+            cycles = (len(cmd.data) + (cmd.address % self.byte_lanes) + self.byte_lanes-1) // self.byte_lanes
 
             resp_cmd = AxiLiteWriteRespCmd(cmd.address, len(cmd.data), cycles, cmd.prot, cmd.event)
-            self.int_write_resp_command_queue.append(resp_cmd)
-            self.int_write_resp_command_sync.set()
+            await self.int_write_resp_command_queue.put(resp_cmd)
 
             offset = 0
 
-            self.log.info("Write start addr: 0x%08x prot: %s data: %s",
-                cmd.address, cmd.prot, ' '.join((f'{c:02x}' for c in cmd.data)))
+            if self.log.isEnabledFor(logging.INFO):
+                self.log.info("Write start addr: 0x%08x prot: %s data: %s",
+                        cmd.address, cmd.prot, ' '.join((f'{c:02x}' for c in cmd.data)))
 
             for k in range(cycles):
                 start = 0
-                stop = self.byte_width
+                stop = self.byte_lanes
                 strb = self.strb_mask
 
                 if k == 0:
@@ -223,7 +266,7 @@ class AxiLiteMasterWrite(Reset):
                     offset += 1
 
                 aw = self.aw_channel._transaction_obj()
-                aw.awaddr = word_addr + k*self.byte_width
+                aw.awaddr = word_addr + k*self.byte_lanes
                 aw.awprot = cmd.prot
 
                 w = self.w_channel._transaction_obj()
@@ -233,34 +276,31 @@ class AxiLiteMasterWrite(Reset):
                 await self.aw_channel.send(aw)
                 await self.w_channel.send(w)
 
+            self.current_write_command = None
+
     async def _process_write_resp(self):
         while True:
-            if not self.int_write_resp_command_queue:
-                self.int_write_resp_command_sync.clear()
-                await self.int_write_resp_command_sync.wait()
-
-            cmd = self.int_write_resp_command_queue.popleft()
+            cmd = await self.int_write_resp_command_queue.get()
+            self.current_write_resp_command = cmd
 
             resp = AxiResp.OKAY
 
             for k in range(cmd.cycles):
                 b = await self.b_channel.recv()
 
-                cycle_resp = AxiResp(b.bresp)
+                cycle_resp = AxiResp(getattr(b, 'bresp', AxiResp.OKAY))
 
                 if cycle_resp != AxiResp.OKAY:
                     resp = cycle_resp
 
             self.log.info("Write complete addr: 0x%08x prot: %s resp: %s length: %d",
-                cmd.address, cmd.prot, resp, cmd.length)
+                    cmd.address, cmd.prot, resp, cmd.length)
 
             write_resp = AxiLiteWriteResp(cmd.address, cmd.length, resp)
 
-            if cmd.event is not None:
-                cmd.event.set(write_resp)
-            else:
-                self.write_resp_queue.append(write_resp)
-                self.write_resp_sync.set()
+            cmd.event.set(write_resp)
+
+            self.current_write_resp_command = None
 
             self.in_flight_operations -= 1
 
@@ -268,8 +308,11 @@ class AxiLiteMasterWrite(Reset):
                 self._idle.set()
 
 
-class AxiLiteMasterRead(Reset):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True):
+class AxiLiteMasterRead(Region, Reset):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, **kwargs):
+        self.bus = bus
+        self.clock = clock
+        self.reset = reset
         self.log = logging.getLogger(f"cocotb.{bus.ar._entity._name}.{bus.ar._name}")
 
         self.log.info("AXI lite master (read)")
@@ -278,30 +321,43 @@ class AxiLiteMasterRead(Reset):
         self.log.info("https://github.com/alexforencich/cocotbext-axi")
 
         self.ar_channel = AxiLiteARSource(bus.ar, clock, reset, reset_active_level)
+        self.ar_channel.queue_occupancy_limit = 2
         self.r_channel = AxiLiteRSink(bus.r, clock, reset, reset_active_level)
+        self.r_channel.queue_occupancy_limit = 2
 
-        self.read_command_queue = deque()
-        self.read_command_sync = Event()
-        self.read_data_queue = deque()
-        self.read_data_sync = Event()
+        self.read_command_queue = Queue()
+        self.current_read_command = None
 
-        self.int_read_resp_command_queue = deque()
-        self.int_read_resp_command_sync = Event()
+        self.int_read_resp_command_queue = Queue()
+        self.current_read_resp_command = None
 
         self.in_flight_operations = 0
         self._idle = Event()
         self._idle.set()
 
+        self.address_width = len(self.ar_channel.bus.araddr)
         self.width = len(self.r_channel.bus.rdata)
         self.byte_size = 8
-        self.byte_width = self.width // self.byte_size
+        self.byte_lanes = self.width // self.byte_size
+
+        self.arprot_present = hasattr(self.bus.ar, "arprot")
+
+        super().__init__(2**self.address_width, **kwargs)
 
         self.log.info("AXI lite master configuration:")
-        self.log.info("  Address width: %d bits", len(self.ar_channel.bus.araddr))
+        self.log.info("  Address width: %d bits", self.address_width)
         self.log.info("  Byte size: %d bits", self.byte_size)
-        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_width)
+        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_lanes)
 
-        assert self.byte_width * self.byte_size == self.width
+        self.log.info("AXI lite master signals:")
+        for bus in (self.bus.ar, self.bus.r):
+            for sig in sorted(list(set().union(bus._signals, bus._optional_signals))):
+                if hasattr(bus, sig):
+                    self.log.info("  %s width: %d bits", sig, len(getattr(bus, sig)))
+                else:
+                    self.log.info("  %s: not present", sig)
+
+        assert self.byte_lanes * self.byte_size == self.width
 
         self._process_read_cr = None
         self._process_read_resp_cr = None
@@ -309,14 +365,24 @@ class AxiLiteMasterRead(Reset):
         self._init_reset(reset, reset_active_level)
 
     def init_read(self, address, length, prot=AxiProt.NONSECURE, event=None):
-        if event is not None and not isinstance(event, Event):
+        if event is None:
+            event = Event()
+
+        if not isinstance(event, Event):
             raise ValueError("Expected event object")
 
+        if address < 0 or address >= 2**self.address_width:
+            raise ValueError("Address out of range")
+
+        if not self.arprot_present and prot != AxiProt.NONSECURE:
+            raise ValueError("arprot sideband signal value specified, but signal is not connected")
+
         self.in_flight_operations += 1
         self._idle.clear()
 
-        self.read_command_queue.append(AxiLiteReadCmd(address, length, prot, event))
-        self.read_command_sync.set()
+        self.read_command_queue.put_nowait(AxiLiteReadCmd(address, length, prot, event))
+
+        return event
 
     def idle(self):
         return not self.in_flight_operations
@@ -325,45 +391,11 @@ class AxiLiteMasterRead(Reset):
         while not self.idle():
             await self._idle.wait()
 
-    def read_data_ready(self):
-        return bool(self.read_data_queue)
-
-    def get_read_data(self):
-        if self.read_data_queue:
-            return self.read_data_queue.popleft()
-        return None
-
     async def read(self, address, length, prot=AxiProt.NONSECURE):
-        event = Event()
-        self.init_read(address, length, prot, event)
+        event = self.init_read(address, length, prot)
         await event.wait()
         return event.data
 
-    async def read_words(self, address, count, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        data = await self.read(address, count*ws, prot)
-        words = []
-        for k in range(count):
-            words.append(int.from_bytes(data.data[ws*k:ws*(k+1)], byteorder))
-        return words
-
-    async def read_dwords(self, address, count, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.read_words(address, count, byteorder, 4, prot)
-
-    async def read_qwords(self, address, count, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.read_words(address, count, byteorder, 8, prot)
-
-    async def read_byte(self, address, prot=AxiProt.NONSECURE):
-        return (await self.read(address, 1, prot)).data[0]
-
-    async def read_word(self, address, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        return (await self.read_words(address, 1, byteorder, ws, prot))[0]
-
-    async def read_dword(self, address, byteorder='little', prot=AxiProt.NONSECURE):
-        return (await self.read_dwords(address, 1, byteorder, prot))[0]
-
-    async def read_qword(self, address, byteorder='little', prot=AxiProt.NONSECURE):
-        return (await self.read_qwords(address, 1, byteorder, prot))[0]
-
     def _handle_reset(self, state):
         if state:
             self.log.info("Reset asserted")
@@ -373,6 +405,35 @@ class AxiLiteMasterRead(Reset):
             if self._process_read_resp_cr is not None:
                 self._process_read_resp_cr.kill()
                 self._process_read_resp_cr = None
+
+            self.ar_channel.clear()
+            self.r_channel.clear()
+
+            def flush_cmd(cmd):
+                self.log.warning("Flushed read operation during reset: %s", cmd)
+                if cmd.event:
+                    cmd.event.set(None)
+
+            while not self.read_command_queue.empty():
+                cmd = self.read_command_queue.get_nowait()
+                flush_cmd(cmd)
+
+            if self.current_read_command:
+                cmd = self.current_read_command
+                self.current_read_command = None
+                flush_cmd(cmd)
+
+            while not self.int_read_resp_command_queue.empty():
+                cmd = self.int_read_resp_command_queue.get_nowait()
+                flush_cmd(cmd)
+
+            if self.current_read_resp_command:
+                cmd = self.current_read_resp_command
+                self.current_read_resp_command = None
+                flush_cmd(cmd)
+
+            self.in_flight_operations = 0
+            self._idle.set()
         else:
             self.log.info("Reset de-asserted")
             if self._process_read_cr is None:
@@ -380,60 +441,37 @@ class AxiLiteMasterRead(Reset):
             if self._process_read_resp_cr is None:
                 self._process_read_resp_cr = cocotb.fork(self._process_read_resp())
 
-        self.ar_channel.clear()
-        self.r_channel.clear()
-
-        while self.read_command_queue:
-            cmd = self.read_command_queue.popleft()
-            if cmd.event:
-                cmd.event.set(None)
-
-        while self.int_read_resp_command_queue:
-            cmd = self.int_read_resp_command_queue.popleft()
-            if cmd.event:
-                cmd.event.set(None)
-
-        self.read_data_queue.clear()
-
-        self.in_flight_operations = 0
-        self._idle.set()
-
     async def _process_read(self):
         while True:
-            if not self.read_command_queue:
-                self.read_command_sync.clear()
-                await self.read_command_sync.wait()
+            cmd = await self.read_command_queue.get()
+            self.current_read_command = cmd
 
-            cmd = self.read_command_queue.popleft()
+            word_addr = (cmd.address // self.byte_lanes) * self.byte_lanes
 
-            word_addr = (cmd.address // self.byte_width) * self.byte_width
-
-            cycles = (cmd.length + self.byte_width-1 + (cmd.address % self.byte_width)) // self.byte_width
+            cycles = (cmd.length + self.byte_lanes-1 + (cmd.address % self.byte_lanes)) // self.byte_lanes
 
             resp_cmd = AxiLiteReadRespCmd(cmd.address, cmd.length, cycles, cmd.prot, cmd.event)
-            self.int_read_resp_command_queue.append(resp_cmd)
-            self.int_read_resp_command_sync.set()
+            await self.int_read_resp_command_queue.put(resp_cmd)
 
             self.log.info("Read start addr: 0x%08x prot: %s length: %d",
-                cmd.address, cmd.prot, cmd.length)
+                    cmd.address, cmd.prot, cmd.length)
 
             for k in range(cycles):
                 ar = self.ar_channel._transaction_obj()
-                ar.araddr = word_addr + k*self.byte_width
+                ar.araddr = word_addr + k*self.byte_lanes
                 ar.arprot = cmd.prot
 
                 await self.ar_channel.send(ar)
 
+            self.current_read_command = None
+
     async def _process_read_resp(self):
         while True:
-            if not self.int_read_resp_command_queue:
-                self.int_read_resp_command_sync.clear()
-                await self.int_read_resp_command_sync.wait()
+            cmd = await self.int_read_resp_command_queue.get()
+            self.current_read_resp_command = cmd
 
-            cmd = self.int_read_resp_command_queue.popleft()
-
-            start_offset = cmd.address % self.byte_width
-            end_offset = ((cmd.address + cmd.length - 1) % self.byte_width) + 1
+            start_offset = cmd.address % self.byte_lanes
+            end_offset = ((cmd.address + cmd.length - 1) % self.byte_lanes) + 1
 
             data = bytearray()
 
@@ -443,13 +481,13 @@ class AxiLiteMasterRead(Reset):
                 r = await self.r_channel.recv()
 
                 cycle_data = int(r.rdata)
-                cycle_resp = AxiResp(r.rresp)
+                cycle_resp = AxiResp(getattr(r, 'rresp', AxiResp.OKAY))
 
                 if cycle_resp != AxiResp.OKAY:
                     resp = cycle_resp
 
                 start = 0
-                stop = self.byte_width
+                stop = self.byte_lanes
 
                 if k == 0:
                     start = start_offset
@@ -459,16 +497,15 @@ class AxiLiteMasterRead(Reset):
                 for j in range(start, stop):
                     data.extend(bytearray([(cycle_data >> j*8) & 0xff]))
 
-            self.log.info("Read complete addr: 0x%08x prot: %s resp: %s data: %s",
-                cmd.address, cmd.prot, resp, ' '.join((f'{c:02x}' for c in data)))
+            if self.log.isEnabledFor(logging.INFO):
+                self.log.info("Read complete addr: 0x%08x prot: %s resp: %s data: %s",
+                        cmd.address, cmd.prot, resp, ' '.join((f'{c:02x}' for c in data)))
 
-            read_resp = AxiLiteReadResp(cmd.address, data, resp)
+            read_resp = AxiLiteReadResp(cmd.address, bytes(data), resp)
 
-            if cmd.event is not None:
-                cmd.event.set(read_resp)
-            else:
-                self.read_data_queue.append(read_resp)
-                self.read_data_sync.set()
+            cmd.event.set(read_resp)
+
+            self.current_read_resp_command = None
 
             self.in_flight_operations -= 1
 
@@ -476,19 +513,21 @@ class AxiLiteMasterRead(Reset):
                 self._idle.set()
 
 
-class AxiLiteMaster:
-    def __init__(self, bus, clock, reset=None, reset_active_level=True):
+class AxiLiteMaster(Region):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, **kwargs):
         self.write_if = None
         self.read_if = None
 
-        self.write_if = AxiLiteMasterWrite(bus.write, clock, reset, reset_active_level)
-        self.read_if = AxiLiteMasterRead(bus.read, clock, reset, reset_active_level)
+        self.write_if = AxiLiteMasterWrite(bus.write, clock, reset, reset_active_level, **kwargs)
+        self.read_if = AxiLiteMasterRead(bus.read, clock, reset, reset_active_level, **kwargs)
+
+        super().__init__(max(self.write_if.size, self.read_if.size), **kwargs)
 
     def init_read(self, address, length, prot=AxiProt.NONSECURE, event=None):
-        self.read_if.init_read(address, length, prot, event)
+        return self.read_if.init_read(address, length, prot, event)
 
     def init_write(self, address, data, prot=AxiProt.NONSECURE, event=None):
-        self.write_if.init_write(address, data, prot, event)
+        return self.write_if.init_write(address, data, prot, event)
 
     def idle(self):
         return (not self.read_if or self.read_if.idle()) and (not self.write_if or self.write_if.idle())
@@ -504,62 +543,8 @@ class AxiLiteMaster:
     async def wait_write(self):
         await self.write_if.wait()
 
-    def read_data_ready(self):
-        return self.read_if.read_data_ready()
-
-    def get_read_data(self):
-        return self.read_if.get_read_data()
-
-    def write_resp_ready(self):
-        return self.write_if.write_resp_ready()
-
-    def get_write_resp(self):
-        return self.write_if.get_write_resp()
-
     async def read(self, address, length, prot=AxiProt.NONSECURE):
         return await self.read_if.read(address, length, prot)
 
-    async def read_words(self, address, count, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        return await self.read_if.read_words(address, count, byteorder, ws, prot)
-
-    async def read_dwords(self, address, count, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.read_if.read_dwords(address, count, byteorder, prot)
-
-    async def read_qwords(self, address, count, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.read_if.read_qwords(address, count, byteorder, prot)
-
-    async def read_byte(self, address, prot=AxiProt.NONSECURE):
-        return await self.read_if.read_byte(address, prot)
-
-    async def read_word(self, address, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        return await self.read_if.read_word(address, byteorder, ws, prot)
-
-    async def read_dword(self, address, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.read_if.read_dword(address, byteorder, prot)
-
-    async def read_qword(self, address, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.read_if.read_qword(address, byteorder, prot)
-
     async def write(self, address, data, prot=AxiProt.NONSECURE):
         return await self.write_if.write(address, data, prot)
-
-    async def write_words(self, address, data, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        return await self.write_if.write_words(address, data, byteorder, ws, prot)
-
-    async def write_dwords(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.write_if.write_dwords(address, data, byteorder, prot)
-
-    async def write_qwords(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.write_if.write_qwords(address, data, byteorder, prot)
-
-    async def write_byte(self, address, data, prot=AxiProt.NONSECURE):
-        return await self.write_if.write_byte(address, data, prot)
-
-    async def write_word(self, address, data, byteorder='little', ws=2, prot=AxiProt.NONSECURE):
-        return await self.write_if.write_word(address, data, byteorder, ws, prot)
-
-    async def write_dword(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.write_if.write_dword(address, data, byteorder, prot)
-
-    async def write_qword(self, address, data, byteorder='little', prot=AxiProt.NONSECURE):
-        return await self.write_if.write_qword(address, data, byteorder, prot)

cocotbext/axi/axil_ram.py

@@ -1,6 +1,6 @@
 """
 
-Copyright (c) 2020 Alex Forencich
+Copyright (c) 2021 Alex Forencich
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -22,171 +22,32 @@ THE SOFTWARE.
 
 """
 
-import logging
-
-import cocotb
-
-from .version import __version__
-from .constants import AxiProt, AxiResp
-from .axil_channels import AxiLiteAWSink, AxiLiteWSink, AxiLiteBSource, AxiLiteARSink, AxiLiteRSource
+from .axil_slave import AxiLiteSlaveWrite, AxiLiteSlaveRead
 from .memory import Memory
-from .reset import Reset
 
 
-class AxiLiteRamWrite(Memory, Reset):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, *args, **kwargs):
-        self.log = logging.getLogger(f"cocotb.{bus.aw._entity._name}.{bus.aw._name}")
+class AxiLiteRamWrite(AxiLiteSlaveWrite, Memory):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, **kwargs):
+        super().__init__(bus, clock, reset, reset_active_level=reset_active_level, size=size, mem=mem, **kwargs)
 
-        self.log.info("AXI lite RAM model (write)")
-        self.log.info("cocotbext-axi version %s", __version__)
-        self.log.info("Copyright (c) 2020 Alex Forencich")
-        self.log.info("https://github.com/alexforencich/cocotbext-axi")
-
-        super().__init__(size, mem, *args, **kwargs)
-
-        self.aw_channel = AxiLiteAWSink(bus.aw, clock, reset, reset_active_level)
-        self.w_channel = AxiLiteWSink(bus.w, clock, reset, reset_active_level)
-        self.b_channel = AxiLiteBSource(bus.b, clock, reset, reset_active_level)
-
-        self.width = len(self.w_channel.bus.wdata)
-        self.byte_size = 8
-        self.byte_width = self.width // self.byte_size
-        self.strb_mask = 2**self.byte_width-1
-
-        self.log.info("AXI lite RAM model configuration:")
-        self.log.info("  Memory size: %d bytes", len(self.mem))
-        self.log.info("  Address width: %d bits", len(self.aw_channel.bus.awaddr))
-        self.log.info("  Byte size: %d bits", self.byte_size)
-        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_width)
-
-        assert self.byte_width == len(self.w_channel.bus.wstrb)
-        assert self.byte_width * self.byte_size == self.width
-
-        self._process_write_cr = None
-
-        self._init_reset(reset, reset_active_level)
-
-    def _handle_reset(self, state):
-        if state:
-            self.log.info("Reset asserted")
-            if self._process_write_cr is not None:
-                self._process_write_cr.kill()
-                self._process_write_cr = None
-        else:
-            self.log.info("Reset de-asserted")
-            if self._process_write_cr is None:
-                self._process_write_cr = cocotb.fork(self._process_write())
-
-        self.aw_channel.clear()
-        self.w_channel.clear()
-        self.b_channel.clear()
-
-    async def _process_write(self):
-        while True:
-            aw = await self.aw_channel.recv()
-
-            addr = (int(aw.awaddr) // self.byte_width) * self.byte_width
-            prot = AxiProt(aw.awprot)
-
-            w = await self.w_channel.recv()
-
-            data = int(w.wdata)
-            strb = int(w.wstrb)
-
-            # todo latency
-
-            self.mem.seek(addr % self.size)
-
-            data = data.to_bytes(self.byte_width, 'little')
-
-            self.log.info("Write data awaddr: 0x%08x awprot: %s wstrb: 0x%02x data: %s",
-                addr, prot, strb, ' '.join((f'{c:02x}' for c in data)))
-
-            for i in range(self.byte_width):
-                if strb & (1 << i):
-                    self.mem.write(data[i:i+1])
-                else:
-                    self.mem.seek(1, 1)
-
-            b = self.b_channel._transaction_obj()
-            b.bresp = AxiResp.OKAY
-
-            await self.b_channel.send(b)
+    async def _write(self, address, data):
+        self.write(address % self.size, data)
 
 
-class AxiLiteRamRead(Memory, Reset):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, *args, **kwargs):
-        self.log = logging.getLogger(f"cocotb.{bus.ar._entity._name}.{bus.ar._name}")
+class AxiLiteRamRead(AxiLiteSlaveRead, Memory):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, **kwargs):
+        super().__init__(bus, clock, reset, reset_active_level=reset_active_level, size=size, mem=mem, **kwargs)
 
-        self.log.info("AXI lite RAM model (read)")
-        self.log.info("cocotbext-axi version %s", __version__)
-        self.log.info("Copyright (c) 2020 Alex Forencich")
-        self.log.info("https://github.com/alexforencich/cocotbext-axi")
-
-        super().__init__(size, mem, *args, **kwargs)
-
-        self.ar_channel = AxiLiteARSink(bus.ar, clock, reset, reset_active_level)
-        self.r_channel = AxiLiteRSource(bus.r, clock, reset, reset_active_level)
-
-        self.width = len(self.r_channel.bus.rdata)
-        self.byte_size = 8
-        self.byte_width = self.width // self.byte_size
-
-        self.log.info("AXI lite RAM model configuration:")
-        self.log.info("  Memory size: %d bytes", len(self.mem))
-        self.log.info("  Address width: %d bits", len(self.ar_channel.bus.araddr))
-        self.log.info("  Byte size: %d bits", self.byte_size)
-        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_width)
-
-        assert self.byte_width * self.byte_size == self.width
-
-        self._process_read_cr = None
-
-        self._init_reset(reset, reset_active_level)
-
-    def _handle_reset(self, state):
-        if state:
-            self.log.info("Reset asserted")
-            if self._process_read_cr is not None:
-                self._process_read_cr.kill()
-                self._process_read_cr = None
-        else:
-            self.log.info("Reset de-asserted")
-            if self._process_read_cr is None:
-                self._process_read_cr = cocotb.fork(self._process_read())
-
-        self.ar_channel.clear()
-        self.r_channel.clear()
-
-    async def _process_read(self):
-        while True:
-            ar = await self.ar_channel.recv()
-
-            addr = (int(ar.araddr) // self.byte_width) * self.byte_width
-            prot = AxiProt(ar.arprot)
-
-            # todo latency
-
-            self.mem.seek(addr % self.size)
-
-            data = self.mem.read(self.byte_width)
-
-            r = self.r_channel._transaction_obj()
-            r.rdata = int.from_bytes(data, 'little')
-            r.rresp = AxiResp.OKAY
-
-            await self.r_channel.send(r)
-
-            self.log.info("Read data araddr: 0x%08x arprot: %s data: %s",
-                addr, prot, ' '.join((f'{c:02x}' for c in data)))
+    async def _read(self, address, length):
+        return self.read(address % self.size, length)
 
 
 class AxiLiteRam(Memory):
-    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, *args, **kwargs):
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, size=1024, mem=None, **kwargs):
         self.write_if = None
         self.read_if = None
 
-        super().__init__(size, mem, *args, **kwargs)
+        super().__init__(size, mem, **kwargs)
 
         self.write_if = AxiLiteRamWrite(bus.write, clock, reset, reset_active_level, mem=self.mem)
         self.read_if = AxiLiteRamRead(bus.read, clock, reset, reset_active_level, mem=self.mem)

cocotbext/axi/axil_slave.py

@@ -0,0 +1,249 @@
+"""
+
+Copyright (c) 2021 Alex Forencich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+"""
+
+import logging
+
+import cocotb
+
+from .version import __version__
+from .constants import AxiProt, AxiResp
+from .axil_channels import AxiLiteAWSink, AxiLiteWSink, AxiLiteBSource, AxiLiteARSink, AxiLiteRSource
+from .reset import Reset
+
+
+class AxiLiteSlaveWrite(Reset):
+    def __init__(self, bus, clock, reset=None, target=None, reset_active_level=True, **kwargs):
+        self.bus = bus
+        self.clock = clock
+        self.reset = reset
+        self.target = target
+        self.log = logging.getLogger(f"cocotb.{bus.aw._entity._name}.{bus.aw._name}")
+
+        self.log.info("AXI lite slave model (write)")
+        self.log.info("cocotbext-axi version %s", __version__)
+        self.log.info("Copyright (c) 2021 Alex Forencich")
+        self.log.info("https://github.com/alexforencich/cocotbext-axi")
+
+        super().__init__(**kwargs)
+
+        self.aw_channel = AxiLiteAWSink(bus.aw, clock, reset, reset_active_level)
+        self.aw_channel.queue_occupancy_limit = 2
+        self.w_channel = AxiLiteWSink(bus.w, clock, reset, reset_active_level)
+        self.w_channel.queue_occupancy_limit = 2
+        self.b_channel = AxiLiteBSource(bus.b, clock, reset, reset_active_level)
+        self.b_channel.queue_occupancy_limit = 2
+
+        self.address_width = len(self.aw_channel.bus.awaddr)
+        self.width = len(self.w_channel.bus.wdata)
+        self.byte_size = 8
+        self.byte_lanes = self.width // self.byte_size
+        self.strb_mask = 2**self.byte_lanes-1
+
+        self.log.info("AXI lite slave model configuration:")
+        self.log.info("  Memory size: %d bytes", len(self.mem))
+        self.log.info("  Address width: %d bits", self.address_width)
+        self.log.info("  Byte size: %d bits", self.byte_size)
+        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_lanes)
+
+        self.log.info("AXI lite slave model signals:")
+        for bus in (self.bus.aw, self.bus.w, self.bus.b):
+            for sig in sorted(list(set().union(bus._signals, bus._optional_signals))):
+                if hasattr(bus, sig):
+                    self.log.info("  %s width: %d bits", sig, len(getattr(bus, sig)))
+                else:
+                    self.log.info("  %s: not present", sig)
+
+        assert self.byte_lanes == len(self.w_channel.bus.wstrb)
+        assert self.byte_lanes * self.byte_size == self.width
+
+        self._process_write_cr = None
+
+        self._init_reset(reset, reset_active_level)
+
+    async def _write(self, address, data):
+        await self.target.write(address, data)
+
+    def _handle_reset(self, state):
+        if state:
+            self.log.info("Reset asserted")
+            if self._process_write_cr is not None:
+                self._process_write_cr.kill()
+                self._process_write_cr = None
+
+            self.aw_channel.clear()
+            self.w_channel.clear()
+            self.b_channel.clear()
+        else:
+            self.log.info("Reset de-asserted")
+            if self._process_write_cr is None:
+                self._process_write_cr = cocotb.fork(self._process_write())
+
+    async def _process_write(self):
+        while True:
+            aw = await self.aw_channel.recv()
+
+            addr = (int(aw.awaddr) // self.byte_lanes) * self.byte_lanes
+            prot = AxiProt(getattr(aw, 'awprot', AxiProt.NONSECURE))
+
+            w = await self.w_channel.recv()
+
+            data = int(w.wdata)
+            strb = int(getattr(w, 'wstrb', self.strb_mask))
+
+            # generate operation list
+            offset = 0
+            start_offset = None
+            write_ops = []
+
+            data = data.to_bytes(self.byte_lanes, 'little')
+
+            b = self.b_channel._transaction_obj()
+            b.bresp = AxiResp.OKAY
+
+            if self.log.isEnabledFor(logging.INFO):
+                self.log.info("Write data awaddr: 0x%08x awprot: %s wstrb: 0x%02x data: %s",
+                        addr, prot, strb, ' '.join((f'{c:02x}' for c in data)))
+
+            for i in range(self.byte_lanes):
+                if strb & (1 << i):
+                    if start_offset is None:
+                        start_offset = offset
+                else:
+                    if start_offset is not None and offset != start_offset:
+                        write_ops.append((addr+start_offset, data[start_offset:offset]))
+                    start_offset = None
+
+                offset += 1
+
+            if start_offset is not None and offset != start_offset:
+                write_ops.append((addr+start_offset, data[start_offset:offset]))
+
+            # perform writes
+            try:
+                for addr, data in write_ops:
+                    await self._write(addr, data)
+            except Exception:
+                self.log.warning("Write operation failed")
+                b.bresp = AxiResp.SLVERR
+
+            await self.b_channel.send(b)
+
+
+class AxiLiteSlaveRead(Reset):
+    def __init__(self, bus, clock, reset=None, target=None, reset_active_level=True, **kwargs):
+        self.bus = bus
+        self.clock = clock
+        self.reset = reset
+        self.target = target
+        self.log = logging.getLogger(f"cocotb.{bus.ar._entity._name}.{bus.ar._name}")
+
+        self.log.info("AXI lite slave model (read)")
+        self.log.info("cocotbext-axi version %s", __version__)
+        self.log.info("Copyright (c) 2021 Alex Forencich")
+        self.log.info("https://github.com/alexforencich/cocotbext-axi")
+
+        super().__init__(**kwargs)
+
+        self.ar_channel = AxiLiteARSink(bus.ar, clock, reset, reset_active_level)
+        self.ar_channel.queue_occupancy_limit = 2
+        self.r_channel = AxiLiteRSource(bus.r, clock, reset, reset_active_level)
+        self.r_channel.queue_occupancy_limit = 2
+
+        self.address_width = len(self.ar_channel.bus.araddr)
+        self.width = len(self.r_channel.bus.rdata)
+        self.byte_size = 8
+        self.byte_lanes = self.width // self.byte_size
+
+        self.log.info("AXI lite slave model configuration:")
+        self.log.info("  Memory size: %d bytes", len(self.mem))
+        self.log.info("  Address width: %d bits", self.address_width)
+        self.log.info("  Byte size: %d bits", self.byte_size)
+        self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_lanes)
+
+        self.log.info("AXI lite slave model signals:")
+        for bus in (self.bus.ar, self.bus.r):
+            for sig in sorted(list(set().union(bus._signals, bus._optional_signals))):
+                if hasattr(bus, sig):
+                    self.log.info("  %s width: %d bits", sig, len(getattr(bus, sig)))
+                else:
+                    self.log.info("  %s: not present", sig)
+
+        assert self.byte_lanes * self.byte_size == self.width
+
+        self._process_read_cr = None
+
+        self._init_reset(reset, reset_active_level)
+
+    async def _read(self, address, length):
+        return await self.target.read(address, length)
+
+    def _handle_reset(self, state):
+        if state:
+            self.log.info("Reset asserted")
+            if self._process_read_cr is not None:
+                self._process_read_cr.kill()
+                self._process_read_cr = None
+
+            self.ar_channel.clear()
+            self.r_channel.clear()
+        else:
+            self.log.info("Reset de-asserted")
+            if self._process_read_cr is None:
+                self._process_read_cr = cocotb.fork(self._process_read())
+
+    async def _process_read(self):
+        while True:
+            ar = await self.ar_channel.recv()
+
+            addr = (int(ar.araddr) // self.byte_lanes) * self.byte_lanes
+            prot = AxiProt(getattr(ar, 'arprot', AxiProt.NONSECURE))
+
+            r = self.r_channel._transaction_obj()
+            r.rresp = AxiResp.OKAY
+
+            try:
+                data = await self._read(addr, self.byte_lanes)
+            except Exception:
+                self.log.warning("Read operation failed")
+                data = bytes(self.byte_lanes)
+                r.rresp = AxiResp.SLVERR
+
+            r.rdata = int.from_bytes(data, 'little')
+
+            await self.r_channel.send(r)
+
+            if self.log.isEnabledFor(logging.INFO):
+                self.log.info("Read data araddr: 0x%08x arprot: %s data: %s",
+                        addr, prot, ' '.join((f'{c:02x}' for c in data)))
+
+
+class AxiLiteSlave:
+    def __init__(self, bus, clock, reset=None, target=None, reset_active_level=True, **kwargs):
+        self.write_if = None
+        self.read_if = None
+
+        super().__init__(**kwargs)
+
+        self.write_if = AxiLiteSlaveWrite(target, bus.write, clock, reset, reset_active_level)
+        self.read_if = AxiLiteSlaveRead(target, bus.read, clock, reset, reset_active_level)

cocotbext/axi/axis.py

@@ -23,12 +23,12 @@ THE SOFTWARE.
 """
 
 import logging
-from collections import deque
 
 import cocotb
+from cocotb.queue import Queue, QueueFull
 from cocotb.triggers import RisingEdge, Timer, First, Event
 from cocotb.utils import get_sim_time
-from cocotb.bus import Bus
+from cocotb_bus.bus import Bus
 
 from .version import __version__
 from .reset import Reset
@@ -276,8 +276,12 @@ class AxiStreamBase(Reset):
         super().__init__(*args, **kwargs)
 
         self.active = False
-        self.queue = deque()
-        self.queue_sync = Event()
+        self.queue = Queue()
+        self.dequeue_event = Event()
+        self.current_frame = None
+        self.idle_event = Event()
+        self.idle_event.set()
+        self.active_event = Event()
 
         self.queue_occupancy_bytes = 0
         self.queue_occupancy_frames = 0
@@ -315,25 +319,13 @@ class AxiStreamBase(Reset):
         self.log.info("AXI stream %s configuration:", self._type)
         self.log.info("  Byte size: %d bits", self.byte_size)
         self.log.info("  Data width: %d bits (%d bytes)", self.width, self.byte_lanes)
-        self.log.info("  tvalid: %s", "present" if hasattr(self.bus, "tvalid") else "not present")
-        self.log.info("  tready: %s", "present" if hasattr(self.bus, "tready") else "not present")
-        self.log.info("  tlast: %s", "present" if hasattr(self.bus, "tlast") else "not present")
-        if hasattr(self.bus, "tkeep"):
-            self.log.info("  tkeep width: %d bits", len(self.bus.tkeep))
-        else:
-            self.log.info("  tkeep: not present")
-        if hasattr(self.bus, "tid"):
-            self.log.info("  tid width: %d bits", len(self.bus.tid))
-        else:
-            self.log.info("  tid: not present")
-        if hasattr(self.bus, "tdest"):
-            self.log.info("  tdest width: %d bits", len(self.bus.tdest))
-        else:
-            self.log.info("  tdest: not present")
-        if hasattr(self.bus, "tuser"):
-            self.log.info("  tuser width: %d bits", len(self.bus.tuser))
-        else:
-            self.log.info("  tuser: not present")
+
+        self.log.info("AXI stream %s signals:", self._type)
+        for sig in sorted(list(set().union(self.bus._signals, self.bus._optional_signals))):
+            if hasattr(self.bus, sig):
+                self.log.info("  %s width: %d bits", sig, len(getattr(self.bus, sig)))
+            else:
+                self.log.info("  %s: not present", sig)
 
         if self.byte_lanes * self.byte_size != self.width:
             raise ValueError(f"Bus does not evenly divide into byte lanes "
@@ -344,13 +336,19 @@ class AxiStreamBase(Reset):
         self._init_reset(reset, reset_active_level)
 
     def count(self):
-        return len(self.queue)
+        return self.queue.qsize()
 
     def empty(self):
-        return not self.queue
+        return self.queue.empty()
 
     def clear(self):
-        self.queue.clear()
+        while not self.queue.empty():
+            frame = self.queue.get_nowait()
+            frame.sim_time_end = None
+            frame.handle_tx_complete()
+        self.dequeue_event.set()
+        self.idle_event.set()
+        self.active_event.clear()
         self.queue_occupancy_bytes = 0
         self.queue_occupancy_frames = 0
 
@@ -360,13 +358,16 @@ class AxiStreamBase(Reset):
             if self._run_cr is not None:
                 self._run_cr.kill()
                 self._run_cr = None
+
+            self.active = False
+
+            if self.queue.empty():
+                self.idle_event.set()
         else:
             self.log.info("Reset de-asserted")
             if self._run_cr is None:
                 self._run_cr = cocotb.fork(self._run())
 
-        self.active = False
-
     async def _run(self):
         raise NotImplementedError()
 
@@ -407,14 +408,32 @@ class AxiStreamSource(AxiStreamBase, AxiStreamPause):
     _valid_init = 0
     _ready_init = None
 
-    async def send(self, frame):
-        self.send_nowait(frame)
+    def __init__(self, bus, clock, reset=None, reset_active_level=True,
+            byte_size=None, byte_lanes=None, *args, **kwargs):
 
-    def send_nowait(self, frame):
+        super().__init__(bus, clock, reset, reset_active_level, byte_size, byte_lanes, *args, **kwargs)
+
+        self.queue_occupancy_limit_bytes = -1
+        self.queue_occupancy_limit_frames = -1
+
+    async def send(self, frame):
+        while self.full():
+            self.dequeue_event.clear()
+            await self.dequeue_event.wait()
         frame = AxiStreamFrame(frame)
+        await self.queue.put(frame)
+        self.idle_event.clear()
+        self.queue_occupancy_bytes += len(frame)
+        self.queue_occupancy_frames += 1
+
+    def send_nowait(self, frame):
+        if self.full():
+            raise QueueFull()
+        frame = AxiStreamFrame(frame)
+        self.queue.put_nowait(frame)
+        self.idle_event.clear()
         self.queue_occupancy_bytes += len(frame)
         self.queue_occupancy_frames += 1
-        self.queue.append(frame)
 
     async def write(self, data):
         await self.send(data)
@@ -422,32 +441,46 @@ class AxiStreamSource(AxiStreamBase, AxiStreamPause):
     def write_nowait(self, data):
         self.send_nowait(data)
 
+    def full(self):
+        if self.queue_occupancy_limit_bytes > 0 and self.queue_occupancy_bytes > self.queue_occupancy_limit_bytes:
+            return True
+        elif self.queue_occupancy_limit_frames > 0 and self.queue_occupancy_frames > self.queue_occupancy_limit_frames:
+            return True
+        else:
+            return False
+
     def idle(self):
         return self.empty() and not self.active
 
     async def wait(self):
-        while not self.idle():
-            await RisingEdge(self.clock)
+        await self.idle_event.wait()
 
     def _handle_reset(self, state):
         super()._handle_reset(state)
 
-        self.bus.tdata <= 0
-        if hasattr(self.bus, "tvalid"):
-            self.bus.tvalid <= 0
-        if hasattr(self.bus, "tlast"):
-            self.bus.tlast <= 0
-        if hasattr(self.bus, "tkeep"):
-            self.bus.tkeep <= 0
-        if hasattr(self.bus, "tid"):
-            self.bus.tid <= 0
-        if hasattr(self.bus, "tdest"):
-            self.bus.tdest <= 0
-        if hasattr(self.bus, "tuser"):
-            self.bus.tuser <= 0
+        if state:
+            self.bus.tdata.value = 0
+            if hasattr(self.bus, "tvalid"):
+                self.bus.tvalid.value = 0
+            if hasattr(self.bus, "tlast"):
+                self.bus.tlast.value = 0
+            if hasattr(self.bus, "tkeep"):
+                self.bus.tkeep.value = 0
+            if hasattr(self.bus, "tid"):
+                self.bus.tid.value = 0
+            if hasattr(self.bus, "tdest"):
+                self.bus.tdest.value = 0
+            if hasattr(self.bus, "tuser"):
+                self.bus.tuser.value = 0
+
+            if self.current_frame:
+                self.log.warning("Flushed transmit frame during reset: %s", self.current_frame)
+                self.current_frame.handle_tx_complete()
+                self.current_frame = None
 
     async def _run(self):
         frame = None
+        frame_offset = 0
         self.active = False
 
         while True:
@@ -458,15 +491,18 @@ class AxiStreamSource(AxiStreamBase, AxiStreamPause):
             tvalid_sample = (not hasattr(self.bus, "tvalid")) or self.bus.tvalid.value
 
             if (tready_sample and tvalid_sample) or not tvalid_sample:
-                if frame is None and self.queue:
-                    frame = self.queue.popleft()
+                if frame is None and not self.queue.empty():
+                    frame = self.queue.get_nowait()
+                    self.dequeue_event.set()
                     self.queue_occupancy_bytes -= len(frame)
                     self.queue_occupancy_frames -= 1
+                    self.current_frame = frame
                     frame.sim_time_start = get_sim_time()
                     frame.sim_time_end = None
                     self.log.info("TX frame: %s", frame)
                     frame.normalize()
                     self.active = True
+                    frame_offset = 0
 
                 if frame and not self.pause:
                     tdata_val = 0
@@ -477,38 +513,42 @@ class AxiStreamSource(AxiStreamBase, AxiStreamPause):
                     tuser_val = 0
 
                     for offset in range(self.byte_lanes):
-                        tdata_val |= (frame.tdata.pop(0) & self.byte_mask) << (offset * self.byte_size)
-                        tkeep_val |= (frame.tkeep.pop(0) & 1) << offset
-                        tid_val = frame.tid.pop(0)
-                        tdest_val = frame.tdest.pop(0)
-                        tuser_val = frame.tuser.pop(0)
+                        tdata_val |= (frame.tdata[frame_offset] & self.byte_mask) << (offset * self.byte_size)
+                        tkeep_val |= (frame.tkeep[frame_offset] & 1) << offset
+                        tid_val = frame.tid[frame_offset]
+                        tdest_val = frame.tdest[frame_offset]
+                        tuser_val = frame.tuser[frame_offset]
+                        frame_offset += 1
 
-                        if len(frame.tdata) == 0:
+                        if frame_offset >= len(frame.tdata):
                             tlast_val = 1
                             frame.sim_time_end = get_sim_time()
                             frame.handle_tx_complete()
                             frame = None
+                            self.current_frame = None
                             break
 
-                    self.bus.tdata <= tdata_val
+                    self.bus.tdata.value = tdata_val
                     if hasattr(self.bus, "tvalid"):
-                        self.bus.tvalid <= 1
+                        self.bus.tvalid.value = 1
                     if hasattr(self.bus, "tlast"):
-                        self.bus.tlast <= tlast_val
+                        self.bus.tlast.value = tlast_val
                     if hasattr(self.bus, "tkeep"):
-                        self.bus.tkeep <= tkeep_val
+                        self.bus.tkeep.value = tkeep_val
                     if hasattr(self.bus, "tid"):
-                        self.bus.tid <= tid_val
+                        self.bus.tid.value = tid_val
                     if hasattr(self.bus, "tdest"):
-                        self.bus.tdest <= tdest_val
+                        self.bus.tdest.value = tdest_val
                     if hasattr(self.bus, "tuser"):
-                        self.bus.tuser <= tuser_val
+                        self.bus.tuser.value = tuser_val
                 else:
                     if hasattr(self.bus, "tvalid"):
-                        self.bus.tvalid <= 0
+                        self.bus.tvalid.value = 0
                     if hasattr(self.bus, "tlast"):
-                        self.bus.tlast <= 0
+                        self.bus.tlast.value = 0
                     self.active = bool(frame)
+                    if not frame and self.queue.empty():
+                        self.idle_event.set()
 
 
 class AxiStreamMonitor(AxiStreamBase):
@@ -527,21 +567,22 @@ class AxiStreamMonitor(AxiStreamBase):
 
         self.read_queue = []
 
+    def _recv(self, frame, compact=True):
+        if self.queue.empty():
+            self.active_event.clear()
+        self.queue_occupancy_bytes -= len(frame)
+        self.queue_occupancy_frames -= 1
+        if compact:
+            frame.compact()
+        return frame
+
     async def recv(self, compact=True):
-        while self.empty():
-            self.queue_sync.clear()
-            await self.queue_sync.wait()
-        return self.recv_nowait(compact)
+        frame = await self.queue.get()
+        return self._recv(frame, compact)
 
     def recv_nowait(self, compact=True):
-        if self.queue:
-            frame = self.queue.popleft()
-            self.queue_occupancy_bytes -= len(frame)
-            self.queue_occupancy_frames -= 1
-            if compact:
-                frame.compact()
-            return frame
-        return None
+        frame = self.queue.get_nowait()
+        return self._recv(frame, compact)
 
     async def read(self, count=-1):
         while not self.read_queue:
@@ -565,11 +606,10 @@ class AxiStreamMonitor(AxiStreamBase):
     async def wait(self, timeout=0, timeout_unit='ns'):
         if not self.empty():
             return
-        self.queue_sync.clear()
         if timeout:
-            await First(self.queue_sync.wait(), Timer(timeout, timeout_unit))
+            await First(self.active_event.wait(), Timer(timeout, timeout_unit))
         else:
-            await self.queue_sync.wait()
+            await self.active_event.wait()
 
     async def _run(self):
         frame = None
@@ -589,9 +629,9 @@ class AxiStreamMonitor(AxiStreamBase):
                     else:
                         frame = AxiStreamFrame([], [], [], [], [])
                     frame.sim_time_start = get_sim_time()
+                    self.active = True
 
                 for offset in range(self.byte_lanes):
-
                     frame.tdata.append((self.bus.tdata.value.integer >> (offset * self.byte_size)) & self.byte_mask)
                     if hasattr(self.bus, "tkeep"):
                         frame.tkeep.append((self.bus.tkeep.value.integer >> offset) & 1)
@@ -609,10 +649,12 @@ class AxiStreamMonitor(AxiStreamBase):
                     self.queue_occupancy_bytes += len(frame)
                     self.queue_occupancy_frames += 1
 
-                    self.queue.append(frame)
-                    self.queue_sync.set()
+                    self.queue.put_nowait(frame)
+                    self.active_event.set()
 
                     frame = None
+            else:
+                self.active = bool(frame)
 
 
 class AxiStreamSink(AxiStreamMonitor, AxiStreamPause):
@@ -643,8 +685,9 @@ class AxiStreamSink(AxiStreamMonitor, AxiStreamPause):
     def _handle_reset(self, state):
         super()._handle_reset(state)
 
-        if hasattr(self.bus, "tready"):
-            self.bus.tready <= 0
+        if state:
+            if hasattr(self.bus, "tready"):
+                self.bus.tready.value = 0
 
     async def _run(self):
         frame = None
@@ -664,9 +707,9 @@ class AxiStreamSink(AxiStreamMonitor, AxiStreamPause):
                     else:
                         frame = AxiStreamFrame([], [], [], [], [])
                     frame.sim_time_start = get_sim_time()
+                    self.active = True
 
                 for offset in range(self.byte_lanes):
-
                     frame.tdata.append((self.bus.tdata.value.integer >> (offset * self.byte_size)) & self.byte_mask)
                     if hasattr(self.bus, "tkeep"):
                         frame.tkeep.append((self.bus.tkeep.value.integer >> offset) & 1)
@@ -684,10 +727,12 @@ class AxiStreamSink(AxiStreamMonitor, AxiStreamPause):
                     self.queue_occupancy_bytes += len(frame)
                     self.queue_occupancy_frames += 1
 
-                    self.queue.append(frame)
-                    self.queue_sync.set()
+                    self.queue.put_nowait(frame)
+                    self.active_event.set()
 
                     frame = None
+            else:
+                self.active = bool(frame)
 
             if hasattr(self.bus, "tready"):
-                self.bus.tready <= (not self.full() and not self.pause)
+                self.bus.tready.value = (not self.full() and not self.pause)

cocotbext/axi/buddy_allocator.py

@@ -0,0 +1,92 @@
+"""
+
+Copyright (c) 2021 Alex Forencich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+"""
+
+
+class BuddyAllocator:
+    def __init__(self, size, min_alloc=1):
+        self.size = size
+        self.min_alloc = min_alloc
+
+        self.free_lists = [[] for x in range((self.size-1).bit_length())]
+        self.free_lists.append([0])
+        self.allocations = {}
+
+    def alloc(self, size):
+        if size < 1 or size > self.size:
+            raise ValueError("size out of range")
+
+        size = max(size, self.min_alloc)
+
+        bucket = (size-1).bit_length()
+        orig_bucket = bucket
+
+        while bucket < len(self.free_lists):
+            if not self.free_lists[bucket]:
+                # find free block
+                bucket += 1
+                continue
+
+            while bucket > orig_bucket:
+                # split block
+                block = self.free_lists[bucket].pop(0)
+                bucket -= 1
+                self.free_lists[bucket].append(block)
+                self.free_lists[bucket].append(block+2**bucket)
+
+            if self.free_lists[bucket]:
+                # allocate
+                block = self.free_lists[bucket].pop(0)
+                self.allocations[block] = bucket
+                return block
+
+            break
+
+        raise Exception("out of memory")
+
+    def free(self, addr):
+        if addr not in self.allocations:
+            raise ValueError("unknown allocation")
+
+        bucket = self.allocations.pop(addr)
+
+        while bucket < len(self.free_lists):
+            size = 2**bucket
+
+            # find buddy
+            if (addr // size) % 2:
+                buddy = addr - size
+            else:
+                buddy = addr + size
+
+            if buddy in self.free_lists[bucket]:
+                # buddy is free, merge
+                self.free_lists[bucket].remove(buddy)
+                addr = min(addr, buddy)
+                bucket += 1
+            else:
+                # buddy is not free, so add to free list
+                self.free_lists[bucket].append(addr)
+                return
+
+        raise Exception("failed to free memory")

cocotbext/axi/memory.py

@@ -28,13 +28,13 @@ from .utils import hexdump, hexdump_lines, hexdump_str
 
 
 class Memory:
-    def __init__(self, size=1024, mem=None, *args, **kwargs):
+    def __init__(self, size=1024, mem=None, **kwargs):
         if mem is not None:
             self.mem = mem
         else:
             self.mem = mmap.mmap(-1, size)
         self.size = len(self.mem)
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
 
     def read(self, address, length):
         self.mem.seek(address)

cocotbext/axi/stream.py

@@ -23,11 +23,11 @@ THE SOFTWARE.
 """
 
 import logging
-from collections import deque
 
 import cocotb
+from cocotb.queue import Queue, QueueFull
 from cocotb.triggers import RisingEdge, Event, First, Timer
-from cocotb.bus import Bus
+from cocotb_bus.bus import Bus
 
 from .reset import Reset
 
@@ -94,8 +94,11 @@ class StreamBase(Reset):
 
         self.active = False
 
-        self.queue = deque()
-        self.queue_sync = Event()
+        self.queue = Queue()
+        self.dequeue_event = Event()
+        self.idle_event = Event()
+        self.idle_event.set()
+        self.active_event = Event()
 
         self.ready = None
         self.valid = None
@@ -124,13 +127,17 @@ class StreamBase(Reset):
         self._init_reset(reset, reset_active_level)
 
     def count(self):
-        return len(self.queue)
+        return self.queue.qsize()
 
     def empty(self):
-        return not self.queue
+        return self.queue.empty()
 
     def clear(self):
-        self.queue.clear()
+        while not self.queue.empty():
+            self.queue.get_nowait()
+        self.dequeue_event.set()
+        self.idle_event.set()
+        self.active_event.clear()
 
     def _handle_reset(self, state):
         if state:
@@ -138,13 +145,16 @@ class StreamBase(Reset):
             if self._run_cr is not None:
                 self._run_cr.kill()
                 self._run_cr = None
+
+            self.active = False
+
+            if self.queue.empty():
+                self.idle_event.set()
         else:
             self.log.info("Reset de-asserted")
             if self._run_cr is None:
                 self._run_cr = cocotb.fork(self._run())
 
-        self.active = False
-
     async def _run(self):
         raise NotImplementedError()
 
@@ -183,24 +193,42 @@ class StreamSource(StreamBase, StreamPause):
     _valid_init = 0
     _ready_init = None
 
+    def __init__(self, bus, clock, reset=None, reset_active_level=True, *args, **kwargs):
+        super().__init__(bus, clock, reset, reset_active_level, *args, **kwargs)
+
+        self.queue_occupancy_limit = -1
+
     async def send(self, obj):
-        self.send_nowait(obj)
+        while self.full():
+            self.dequeue_event.clear()
+            await self.dequeue_event.wait()
+        await self.queue.put(obj)
+        self.idle_event.clear()
 
     def send_nowait(self, obj):
-        self.queue.append(obj)
+        if self.full():
+            raise QueueFull()
+        self.queue.put_nowait(obj)
+        self.idle_event.clear()
+
+    def full(self):
+        if self.queue_occupancy_limit > 0 and self.count() >= self.queue_occupancy_limit:
+            return True
+        else:
+            return False
 
     def idle(self):
         return self.empty() and not self.active
 
     async def wait(self):
-        while not self.idle():
-            await RisingEdge(self.clock)
+        await self.idle_event.wait()
 
     def _handle_reset(self, state):
         super()._handle_reset(state)
 
-        if self.valid is not None:
-            self.valid <= 0
+        if state:
+            if self.valid is not None:
+                self.valid.value = 0
 
     async def _run(self):
         while True:
@@ -211,15 +239,18 @@ class StreamSource(StreamBase, StreamPause):
             valid_sample = self.valid is None or self.valid.value
 
             if (ready_sample and valid_sample) or (not valid_sample):
-                if self.queue and not self.pause:
-                    self.bus.drive(self.queue.popleft())
+                if not self.queue.empty() and not self.pause:
+                    self.bus.drive(self.queue.get_nowait())
+                    self.dequeue_event.set()
                     if self.valid is not None:
-                        self.valid <= 1
+                        self.valid.value = 1
                     self.active = True
                 else:
                     if self.valid is not None:
-                        self.valid <= 0
-                    self.active = bool(self.queue)
+                        self.valid.value = 0
+                    self.active = not self.queue.empty()
+                    if self.queue.empty():
+                        self.idle_event.set()
 
 
 class StreamMonitor(StreamBase):
@@ -229,25 +260,26 @@ class StreamMonitor(StreamBase):
     _valid_init = None
     _ready_init = None
 
+    def _recv(self, item):
+        if self.queue.empty():
+            self.active_event.clear()
+        return item
+
     async def recv(self):
-        while self.empty():
-            self.queue_sync.clear()
-            await self.queue_sync.wait()
-        return self.recv_nowait()
+        item = await self.queue.get()
+        return self._recv(item)
 
     def recv_nowait(self):
-        if self.queue:
-            return self.queue.popleft()
-        return None
+        item = self.queue.get_nowait()
+        return self._recv(item)
 
     async def wait(self, timeout=0, timeout_unit=None):
         if not self.empty():
             return
-        self.queue_sync.clear()
         if timeout:
-            await First(self.queue_sync.wait(), Timer(timeout, timeout_unit))
+            await First(self.active_event.wait(), Timer(timeout, timeout_unit))
         else:
-            await self.queue_sync.wait()
+            await self.active_event.wait()
 
     async def _run(self):
         while True:
@@ -260,8 +292,8 @@ class StreamMonitor(StreamBase):
             if ready_sample and valid_sample:
                 obj = self._transaction_obj()
                 self.bus.sample(obj)
-                self.queue.append(obj)
-                self.queue_sync.set()
+                self.queue.put_nowait(obj)
+                self.active_event.set()
 
 
 class StreamSink(StreamMonitor, StreamPause):
@@ -277,7 +309,7 @@ class StreamSink(StreamMonitor, StreamPause):
         self.queue_occupancy_limit = -1
 
     def full(self):
-        if self.queue_occupancy_limit > 0 and len(self.queue) >= self.queue_occupancy_limit:
+        if self.queue_occupancy_limit > 0 and self.count() >= self.queue_occupancy_limit:
             return True
         else:
             return False
@@ -285,8 +317,9 @@ class StreamSink(StreamMonitor, StreamPause):
     def _handle_reset(self, state):
         super()._handle_reset(state)
 
-        if self.ready is not None:
-            self.ready <= 0
+        if state:
+            if self.ready is not None:
+                self.ready.value = 0
 
     async def _run(self):
         while True:
@@ -299,11 +332,11 @@ class StreamSink(StreamMonitor, StreamPause):
             if ready_sample and valid_sample:
                 obj = self._transaction_obj()
                 self.bus.sample(obj)
-                self.queue.append(obj)
-                self.queue_sync.set()
+                self.queue.put_nowait(obj)
+                self.active_event.set()
 
             if self.ready is not None:
-                self.ready <= (not self.full() and not self.pause)
+                self.ready.value = (not self.full() and not self.pause)
 
 
 def define_stream(name, signals, optional_signals=None, valid_signal=None, ready_signal=None, signal_widths=None):

cocotbext/axi/version.py

@@ -1 +1 @@
-__version__ = "0.1.6"
+__version__ = "0.1.16"

setup.cfg

@@ -17,9 +17,10 @@ long-description-content-type = text/markdown
 platforms = any
 classifiers =
     Development Status :: 3 - Alpha
-    Programming Language :: Python :: 3
+    Framework :: cocotb
     License :: OSI Approved :: MIT License
     Operating System :: OS Independent
+    Programming Language :: Python :: 3
     Topic :: Scientific/Engineering :: Electronic Design Automation (EDA)
 
 [options]
@@ -27,6 +28,7 @@ packages = find_namespace:
 python_requires = >=3.6
 install_requires =
     cocotb
+    cocotb-bus
 
 [options.extras_require]
 test =

tests/axi/test_axi.py

@@ -73,10 +73,10 @@ class TB:
         self.dut.rst.setimmediatevalue(0)
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
-        self.dut.rst <= 1
+        self.dut.rst.value = 1
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
-        self.dut.rst <= 0
+        self.dut.rst.value = 0
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
 
@@ -85,7 +85,7 @@ async def run_test_write(dut, idle_inserter=None, backpressure_inserter=None, si
 
     tb = TB(dut)
 
-    byte_width = tb.axi_master.write_if.byte_width
+    byte_lanes = tb.axi_master.write_if.byte_lanes
     max_burst_size = tb.axi_master.write_if.max_burst_size
 
     if size is None:
@@ -96,8 +96,8 @@ async def run_test_write(dut, idle_inserter=None, backpressure_inserter=None, si
     tb.set_idle_generator(idle_inserter)
     tb.set_backpressure_generator(backpressure_inserter)
 
-    for length in list(range(1, byte_width*2))+[1024]:
-        for offset in list(range(byte_width))+list(range(4096-byte_width, 4096)):
+    for length in list(range(1, byte_lanes*2))+[1024]:
+        for offset in list(range(byte_lanes))+list(range(4096-byte_lanes, 4096)):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
             test_data = bytearray([x % 256 for x in range(length)])
@@ -120,7 +120,7 @@ async def run_test_read(dut, idle_inserter=None, backpressure_inserter=None, siz
 
     tb = TB(dut)
 
-    byte_width = tb.axi_master.write_if.byte_width
+    byte_lanes = tb.axi_master.write_if.byte_lanes
     max_burst_size = tb.axi_master.write_if.max_burst_size
 
     if size is None:
@@ -131,8 +131,8 @@ async def run_test_read(dut, idle_inserter=None, backpressure_inserter=None, siz
     tb.set_idle_generator(idle_inserter)
     tb.set_backpressure_generator(backpressure_inserter)
 
-    for length in list(range(1, byte_width*2))+[1024]:
-        for offset in list(range(byte_width))+list(range(4096-byte_width, 4096)):
+    for length in list(range(1, byte_lanes*2))+[1024]:
+        for offset in list(range(byte_lanes))+list(range(4096-byte_lanes, 4096)):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
             test_data = bytearray([x % 256 for x in range(length)])
@@ -151,15 +151,20 @@ async def run_test_write_words(dut):
 
     tb = TB(dut)
 
-    byte_width = tb.axi_master.write_if.byte_width
+    byte_lanes = tb.axi_master.write_if.byte_lanes
 
     await tb.cycle_reset()
 
     for length in list(range(1, 4)):
-        for offset in list(range(byte_width)):
+        for offset in list(range(byte_lanes)):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
 
+            test_data = bytearray([x % 256 for x in range(length)])
+            event = tb.axi_master.init_write(addr, test_data)
+            await event.wait()
+            assert tb.axi_ram.read(addr, length) == test_data
+
             test_data = bytearray([x % 256 for x in range(length)])
             await tb.axi_master.write(addr, test_data)
             assert tb.axi_ram.read(addr, length) == test_data
@@ -200,15 +205,21 @@ async def run_test_read_words(dut):
 
     tb = TB(dut)
 
-    byte_width = tb.axi_master.write_if.byte_width
+    byte_lanes = tb.axi_master.write_if.byte_lanes
 
     await tb.cycle_reset()
 
     for length in list(range(1, 4)):
-        for offset in list(range(byte_width)):
+        for offset in list(range(byte_lanes)):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
 
+            test_data = bytearray([x % 256 for x in range(length)])
+            tb.axi_ram.write(addr, test_data)
+            event = tb.axi_master.init_read(addr, length)
+            await event.wait()
+            assert event.data.data == test_data
+
             test_data = bytearray([x % 256 for x in range(length)])
             tb.axi_ram.write(addr, test_data)
             assert (await tb.axi_master.read(addr, length)).data == test_data
@@ -287,9 +298,9 @@ def cycle_pause():
 
 if cocotb.SIM_NAME:
 
-    data_width = int(os.getenv("PARAM_DATA_WIDTH"))
-    byte_width = data_width // 8
-    max_burst_size = (byte_width-1).bit_length()
+    data_width = len(cocotb.top.axi_wdata)
+    byte_lanes = data_width // 8
+    max_burst_size = (byte_lanes-1).bit_length()
 
     for test in [run_test_write, run_test_read]:
 

tests/axil/test_axil.py

@@ -70,10 +70,10 @@ class TB:
         self.dut.rst.setimmediatevalue(0)
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
-        self.dut.rst <= 1
+        self.dut.rst.value = 1
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
-        self.dut.rst <= 0
+        self.dut.rst.value = 0
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
 
@@ -82,15 +82,15 @@ async def run_test_write(dut, data_in=None, idle_inserter=None, backpressure_ins
 
     tb = TB(dut)
 
-    byte_width = tb.axil_master.write_if.byte_width
+    byte_lanes = tb.axil_master.write_if.byte_lanes
 
     await tb.cycle_reset()
 
     tb.set_idle_generator(idle_inserter)
     tb.set_backpressure_generator(backpressure_inserter)
 
-    for length in range(1, byte_width*2):
-        for offset in range(byte_width):
+    for length in range(1, byte_lanes*2):
+        for offset in range(byte_lanes):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
             test_data = bytearray([x % 256 for x in range(length)])
@@ -113,15 +113,15 @@ async def run_test_read(dut, data_in=None, idle_inserter=None, backpressure_inse
 
     tb = TB(dut)
 
-    byte_width = tb.axil_master.write_if.byte_width
+    byte_lanes = tb.axil_master.write_if.byte_lanes
 
     await tb.cycle_reset()
 
     tb.set_idle_generator(idle_inserter)
     tb.set_backpressure_generator(backpressure_inserter)
 
-    for length in range(1, byte_width*2):
-        for offset in range(byte_width):
+    for length in range(1, byte_lanes*2):
+        for offset in range(byte_lanes):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
             test_data = bytearray([x % 256 for x in range(length)])
@@ -140,15 +140,20 @@ async def run_test_write_words(dut):
 
     tb = TB(dut)
 
-    byte_width = tb.axil_master.write_if.byte_width
+    byte_lanes = tb.axil_master.write_if.byte_lanes
 
     await tb.cycle_reset()
 
     for length in list(range(1, 4)):
-        for offset in list(range(byte_width)):
+        for offset in list(range(byte_lanes)):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
 
+            test_data = bytearray([x % 256 for x in range(length)])
+            event = tb.axil_master.init_write(addr, test_data)
+            await event.wait()
+            assert tb.axil_ram.read(addr, length) == test_data
+
             test_data = bytearray([x % 256 for x in range(length)])
             await tb.axil_master.write(addr, test_data)
             assert tb.axil_ram.read(addr, length) == test_data
@@ -189,15 +194,21 @@ async def run_test_read_words(dut):
 
     tb = TB(dut)
 
-    byte_width = tb.axil_master.write_if.byte_width
+    byte_lanes = tb.axil_master.write_if.byte_lanes
 
     await tb.cycle_reset()
 
     for length in list(range(1, 4)):
-        for offset in list(range(byte_width)):
+        for offset in list(range(byte_lanes)):
             tb.log.info("length %d, offset %d", length, offset)
             addr = offset+0x1000
 
+            test_data = bytearray([x % 256 for x in range(length)])
+            tb.axil_ram.write(addr, test_data)
+            event = tb.axil_master.init_read(addr, length)
+            await event.wait()
+            assert event.data.data == test_data
+
             test_data = bytearray([x % 256 for x in range(length)])
             tb.axil_ram.write(addr, test_data)
             assert (await tb.axil_master.read(addr, length)).data == test_data

tests/axis/test_axis.py

@@ -63,10 +63,10 @@ class TB:
         self.dut.rst.setimmediatevalue(0)
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
-        self.dut.rst <= 1
+        self.dut.rst.value = 1
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
-        self.dut.rst <= 0
+        self.dut.rst.value = 0
         await RisingEdge(self.dut.clk)
         await RisingEdge(self.dut.clk)
 
@@ -126,7 +126,7 @@ def cycle_pause():
 
 
 def size_list():
-    data_width = int(os.getenv("PARAM_DATA_WIDTH"))
+    data_width = len(cocotb.top.axis_tdata)
     byte_width = data_width // 8
     return list(range(1, byte_width*4+1)) + [512] + [1]*64
 

tests/test_buddy_allocator.py

@@ -0,0 +1,44 @@
+"""
+
+Copyright (c) 2021 Alex Forencich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+"""
+
+from cocotbext.axi.buddy_allocator import BuddyAllocator
+
+
+def test_allocator():
+    ba = BuddyAllocator(1024)
+
+    lst = []
+
+    for k in range(1, 32):
+        print(f"Alloc {k} bytes")
+        addr = ba.alloc(k)
+        print(f"Got address {addr}")
+        assert addr & (2**((k-1).bit_length())-1) == 0
+        lst.append(addr)
+
+    for addr in lst:
+        print(f"Free {addr}")
+        ba.free(addr)
+
+    assert ba.free_lists[-1] == [0]