Implement read buffering. (#22)

src/peakrdl_regblock/read_buffering/__init__.py

@@ -0,0 +1,58 @@
+from typing import TYPE_CHECKING
+
+from systemrdl.node import AddrmapNode, RegNode, FieldNode, SignalNode
+
+from .storage_generator import RBufStorageStructGenerator
+from .implementation_generator import RBufLogicGenerator
+from ..utils import get_indexed_path
+
+if TYPE_CHECKING:
+    from ..exporter import RegblockExporter
+
+
+class ReadBuffering:
+    def __init__(self, exp:'RegblockExporter'):
+        self.exp = exp
+
+    @property
+    def top_node(self) -> 'AddrmapNode':
+        return self.exp.top_node
+
+    def get_storage_struct(self) -> str:
+        struct_gen = RBufStorageStructGenerator()
+        s = struct_gen.get_struct(self.top_node, "rbuf_storage_t")
+        assert s is not None
+        return s + "\nrbuf_storage_t rbuf_storage;"
+
+    def get_implementation(self) -> str:
+        gen = RBufLogicGenerator(self)
+        s = gen.get_content(self.top_node)
+        assert s is not None
+        return s
+
+    def get_trigger(self, node: RegNode) -> str:
+        trigger = node.get_property('rbuffer_trigger')
+
+        if isinstance(trigger, RegNode):
+            # Trigger is a register.
+            # trigger when lowermost address of the register is written
+            regwidth = node.get_property('regwidth')
+            accesswidth = node.get_property('accesswidth')
+            strb_prefix = self.exp.dereferencer.get_access_strobe(trigger, reduce_substrobes=False)
+
+            if accesswidth < regwidth:
+                return f"{strb_prefix}[0] && !decoded_req_is_wr"
+            else:
+                return f"{strb_prefix} && !decoded_req_is_wr"
+        elif isinstance(trigger, SignalNode):
+            s = self.exp.dereferencer.get_value(trigger)
+            if trigger.get_property('activehigh'):
+                return s
+            else:
+                return f"~{s}"
+        else:
+            # Trigger is a field or propref bit
+            return self.exp.dereferencer.get_value(trigger)
+
+    def get_rbuf_data(self, node: RegNode) -> str:
+        return "rbuf_storage." + get_indexed_path(self.top_node, node) + ".data"