fill in more hwif utility functions for dereferencer

peakrdl/regblock/field_logic/sw_onread.py

@@ -0,0 +1,38 @@
+from typing import TYPE_CHECKING, List
+
+from systemrdl.rdltypes import OnReadType
+
+from .bases import NextStateConditional
+
+if TYPE_CHECKING:
+    from systemrdl.node import FieldNode
+
+class _OnRead(NextStateConditional):
+    onreadtype = None
+    def is_match(self, field: 'FieldNode') -> bool:
+        return field.get_property("onread") == self.onreadtype
+
+    def get_conditional(self, field: 'FieldNode') -> str:
+        strb = self.exporter.dereferencer.get_access_strobe(field)
+        return f"decoded_req && !decoded_req_is_wr && {strb}"
+
+class ClearOnRead(_OnRead):
+    onreadtype = OnReadType.rclr
+
+    def get_assignments(self, field: 'FieldNode') -> List[str]:
+        field_path = self.get_field_path(field)
+        return [
+            f"field_combo.{field_path}.next = '0;",
+            f"field_combo.{field_path}.load_next = '1;",
+        ]
+
+
+class SetOnRead(_OnRead):
+    onreadtype = OnReadType.rset
+
+    def get_assignments(self, field: 'FieldNode') -> List[str]:
+        field_path = self.get_field_path(field)
+        return [
+            f"field_combo.{field_path}.next = '1;",
+            f"field_combo.{field_path}.load_next = '1;",
+        ]