Add validation check for write buffered registers that trigger off of…

… their own field. #39

src/peakrdl_regblock/udps/rw_buffering.py

@@ -4,7 +4,7 @@
 from systemrdl.component import Reg
 from systemrdl.rdltypes.references import RefType, PropertyReference
 from systemrdl.rdltypes import NoValue
-from systemrdl.node import Node, RegNode, VectorNode, SignalNode
+from systemrdl.node import Node, RegNode, VectorNode, SignalNode, FieldNode
 
 
 class xBufferTrigger(UDPDefinition):
@@ -91,6 +91,16 @@ def get_unassigned_default(self, node: 'Node') -> Any:
             return node
         return None
 
+    def validate(self, node: Node, value: Any) -> None:
+        super().validate(node, value)
+
+        if isinstance(value, FieldNode):
+            if value.parent == node:
+                self.msg.error(
+                    "Trigger for a write-buffered register cannot be a field "
+                    "within the same register since the buffering makes it impossible to trigger."
+                )
+
 
 class BufferReads(UDPDefinition):
     name = "buffer_reads"