Collapse hwif into one file

doc/logbooks/template-layers/4-fields

@@ -7,26 +7,30 @@ Any field that implements storage is defined here.
 Bigass struct that only contains storage elements
 
 Each field consists of:
-    - an always_ff block
+    - an always_comb block:
+        - generates the "next value" combinational signal
+        - May generate other intermediate strobes?
+            incr/decr?
         - series of if/else statements that assign the next value in the storage element
             Think of this as a flat list of "next state" conditons, ranked by their precedence as follows:
                 - reset
+                    Actually, handle this in the always_ff
                 - sw access (if sw precedence)
                     - onread/onwrite
                 - hw access
                     - Counter
+                        beware of clear events and incr/decr events happening simultaneously
                     - next
                     - etc
                 - sw access (if hw precedence)
                     - onread/onwrite
-
+        - always_comb block to also generate write-enable strobes for the actual
-TODO:
+          storage element
-    What about stuff like read-clear counters that cant lose a count?
+          This is better for low-power design
-    In a traditional if/else chain, i need to be aware of the fact that its a counter
+    - an always_ff block
-    when handling the swaccess case
+        Implements the actual storage element
-    Is it possible to code this in a way where I can isolate the need to know every nuanced case here?
+        Also a tidy place to abstract the specifics of activehigh/activelow field reset
-        this may actually only apply to counters...
+        selection.
-    This is trivial in a 2-process implementation, but i'd rather avoid the overheads
 
 TODO:
     Scour the RDL spec.

peakrdl/regblock/dereferencer.py

@@ -4,7 +4,7 @@ from systemrdl.rdltypes import PropertyReference
 
 if TYPE_CHECKING:
     from .exporter import RegblockExporter
-    from .hwif.base import HwifBase
+    from .hwif import Hwif
     from .field_logic import FieldLogic
     from .addr_decode import AddressDecode
 
@@ -13,7 +13,7 @@ class Dereferencer:
     This class provides an interface to convert conceptual SystemRDL references
     into Verilog identifiers
     """
-    def __init__(self, exporter:'RegblockExporter', top_node:Node, hwif:'HwifBase', address_decode: 'AddressDecode', field_logic: 'FieldLogic'):
+    def __init__(self, exporter:'RegblockExporter', top_node:Node, hwif:'Hwif', address_decode: 'AddressDecode', field_logic: 'FieldLogic'):
         self.exporter = exporter
         self.hwif = hwif
         self.address_decode = address_decode

peakrdl/regblock/exporter.py

@@ -11,7 +11,7 @@ from .readback_mux import ReadbackMux
 from .signals import InferredSignal
 
 from .cpuif.apb4 import APB4_Cpuif
-from .hwif.struct import StructHwif
+from .hwif import Hwif
 
 class RegblockExporter:
     def __init__(self, **kwargs):
@@ -50,7 +50,7 @@ class RegblockExporter:
             node = node.top
 
         cpuif_cls = kwargs.pop("cpuif_cls", APB4_Cpuif)
-        hwif_cls = kwargs.pop("hwif_cls", StructHwif)
+        hwif_cls = kwargs.pop("hwif_cls", Hwif)
         module_name = kwargs.pop("module_name", node.inst_name)
         package_name = kwargs.pop("package_name", module_name + "_pkg")
 

peakrdl/regblock/hwif.py

@@ -1,16 +1,22 @@
-from typing import Union, List, TYPE_CHECKING
+from typing import TYPE_CHECKING, Union, List
-
+from systemrdl.node import Node, SignalNode, FieldNode, AddressableNode
-from systemrdl.node import Node, AddressableNode, FieldNode, SignalNode
+from systemrdl.rdltypes import PropertyReference
-
-from .base import HwifBase
 
 if TYPE_CHECKING:
-    from ..exporter import RegblockExporter
+    from .exporter import RegblockExporter
 
-class StructHwif(HwifBase):
+class Hwif:
+    """
+    Defines how the hardware input/output signals are generated:
+    - Field outputs
+    - Field inputs
+    - Signal inputs (except those that are promoted to the top)
+    """
 
-    def __init__(self, exporter:'RegblockExporter', top_node:Node, package_name:str):
+    def __init__(self, exporter: 'RegblockExporter', top_node: Node, package_name: str):
-        super().__init__(exporter, top_node, package_name)
+        self.exporter = exporter
+        self.top_node = top_node
+        self.package_name = package_name
 
         self.has_input_struct = None
         self.has_output_struct = None
@@ -18,6 +24,9 @@ class StructHwif(HwifBase):
 
 
     def get_package_declaration(self) -> str:
+        """
+        If this hwif requires a package, generate the string
+        """
         lines = []
 
         lines.append(f"package {self.package_name};")
@@ -49,6 +58,7 @@ class StructHwif(HwifBase):
 
         return ",\n".join(lines)
 
+
     #---------------------------------------------------------------------------
     # Struct generation functions
     #---------------------------------------------------------------------------
@@ -180,3 +190,58 @@ class StructHwif(HwifBase):
         """
 
         return contents
+
+    #---------------------------------------------------------------------------
+    # hwif utility functions
+    #---------------------------------------------------------------------------
+    def has_value_input(self, obj: Union[FieldNode, SignalNode]) -> bool:
+        """
+        Returns True if the object infers an input wire in the hwif
+        """
+        if isinstance(obj, FieldNode):
+            return obj.is_hw_writable
+        elif isinstance(obj, SignalNode):
+            # Signals are implicitly always inputs
+            return True
+        else:
+            raise RuntimeError
+
+
+    def has_value_output(self, obj: FieldNode) -> bool:
+        """
+        Returns True if the object infers an output wire in the hwif
+        """
+        # TODO: Extend this for signals and prop references?
+        return obj.is_hw_readable
+
+
+    def get_input_identifier(self, obj: Union[FieldNode, SignalNode, PropertyReference]) -> str:
+        """
+        Returns the identifier string that best represents the input object.
+
+        if obj is:
+            Field: the fields input value port
+            Signal: signal input value
+            Prop reference:
+                could be an implied hwclr/hwset/swwe/swwel/we/wel input
+                Raise a runtime error if an illegal prop ref is requested, or if
+                the prop ref is not actually implied, but explicitly ref a component
+
+        TODO: finish this
+        raises an exception if obj is invalid
+        """
+        raise NotImplementedError()
+
+
+    def get_output_identifier(self, obj: FieldNode) -> str:
+        """
+        Returns the identifier string that best represents the output object.
+
+        if obj is:
+            Field: the fields output value port
+            Property ref: this is also part of the struct
+            TODO: finish this
+
+        raises an exception if obj is invalid
+        """
+        raise NotImplementedError()

peakrdl/regblock/hwif/__init__.py

@@ -1 +0,0 @@
-from .base import HwifBase

peakrdl/regblock/hwif/base.py

@@ -1,89 +0,0 @@
-from typing import TYPE_CHECKING, Union
-from systemrdl.node import Node, SignalNode, FieldNode
-from systemrdl.rdltypes import AccessType, PropertyReference
-
-if TYPE_CHECKING:
-    from ..exporter import RegblockExporter
-
-class HwifBase:
-    """
-    Defines how the hardware input/output signals are generated:
-    - Field outputs
-    - Field inputs
-    - Signal inputs (except those that are promoted to the top)
-    """
-
-    def __init__(self, exporter: 'RegblockExporter', top_node: Node, package_name: str):
-        self.exporter = exporter
-        self.top_node = top_node
-        self.package_name = package_name
-
-
-    def get_package_declaration(self) -> str:
-        """
-        If this hwif requires a package, generate the string
-        """
-        return ""
-
-
-    @property
-    def port_declaration(self) -> str:
-        """
-        Returns the declaration string for all I/O ports in the hwif group
-        """
-        raise NotImplementedError()
-
-    #---------------------------------------------------------------------------
-    # hwif utility functions
-    #---------------------------------------------------------------------------
-    def has_value_input(self, obj: Union[FieldNode, SignalNode]) -> bool:
-        """
-        Returns True if the object infers an input wire in the hwif
-        """
-        if isinstance(obj, FieldNode):
-            return obj.is_hw_writable
-        elif isinstance(obj, SignalNode):
-            # Signals are implicitly always inputs
-            return True
-        else:
-            raise RuntimeError
-
-
-    def has_value_output(self, obj: FieldNode) -> bool:
-        """
-        Returns True if the object infers an output wire in the hwif
-        """
-        # TODO: Extend this for signals and prop references?
-        return obj.is_hw_readable
-
-
-    def get_input_identifier(self, obj: Union[FieldNode, SignalNode, PropertyReference]) -> str:
-        """
-        Returns the identifier string that best represents the input object.
-
-        if obj is:
-            Field: the fields input value port
-            Signal: signal input value
-            Prop reference:
-                could be an implied hwclr/hwset/swwe/swwel/we/wel input
-                Raise a runtime error if an illegal prop ref is requested, or if
-                the prop ref is not actually implied, but explicitly ref a component
-
-        TODO: finish this
-        raises an exception if obj is invalid
-        """
-        raise NotImplementedError()
-
-
-    def get_output_identifier(self, obj: FieldNode) -> str:
-        """
-        Returns the identifier string that best represents the output object.
-
-        if obj is:
-            Field: the fields output value port
-            Property ref: this is also part of the struct
-            TODO: finish this
-
-        raises an exception if obj is invalid
-        """
-        raise NotImplementedError()