Fix missing error message if multiple unconditional field assignments are inferred. #93

src/peakrdl_regblock/field_logic/hw_write.py

@@ -1,18 +1,17 @@
 from typing import TYPE_CHECKING, List
 
-from .bases import NextStateConditional
+from .bases import NextStateConditional, NextStateUnconditional
 
 if TYPE_CHECKING:
     from systemrdl.node import FieldNode
 
 
-class AlwaysWrite(NextStateConditional):
+class AlwaysWrite(NextStateUnconditional):
     """
     hw writable, without any qualifying we/wel
     """
-
-    is_unconditional = True
     comment = "HW Write"
+    unconditional_explanation = "A hardware-writable field without a write-enable (we/wel) will always update the field value"
 
     def is_match(self, field: 'FieldNode') -> bool:
         return (
@@ -40,8 +39,28 @@ class AlwaysWrite(NextStateConditional):
             "load_next_c = '1;",
         ]
 
-class WEWrite(AlwaysWrite):
-    is_unconditional = False
+
+class _QualifiedWrite(NextStateConditional):
+    def get_assignments(self, field: 'FieldNode') -> List[str]:
+        hwmask = field.get_property('hwmask')
+        hwenable = field.get_property('hwenable')
+        I = str(self.exp.hwif.get_input_identifier(field))
+        R = self.exp.field_logic.get_storage_identifier(field)
+        if hwmask is not None:
+            M = self.exp.dereferencer.get_value(hwmask)
+            next_val = f"{I} & ~{M} | {R} & {M}"
+        elif hwenable is not None:
+            E = self.exp.dereferencer.get_value(hwenable)
+            next_val = f"{I} & {E} | {R} & ~{E}"
+        else:
+            next_val = I
+
+        return [
+            f"next_c = {next_val};",
+            "load_next_c = '1;",
+        ]
+
+class WEWrite(_QualifiedWrite):
     comment = "HW Write - we"
     def is_match(self, field: 'FieldNode') -> bool:
         return (
@@ -58,8 +77,7 @@ class WEWrite(AlwaysWrite):
             identifier = str(self.exp.dereferencer.get_value(prop))
         return identifier
 
-class WELWrite(AlwaysWrite):
-    is_unconditional = False
+class WELWrite(_QualifiedWrite):
     comment = "HW Write - wel"
     def is_match(self, field: 'FieldNode') -> bool:
         return (