more field logic

peakrdl/regblock/field_logic/hw_write.py

@@ -0,0 +1,78 @@
+from typing import TYPE_CHECKING, List
+
+from .bases import NextStateConditional
+
+if TYPE_CHECKING:
+    from systemrdl.node import FieldNode
+
+
+class AlwaysWrite(NextStateConditional):
+    """
+    hw writable, without any qualifying we/wel
+    """
+    comment = "HW Write"
+    def is_match(self, field: 'FieldNode') -> bool:
+        return (
+            field.is_hw_writable
+            and not field.get_property('we')
+            and not field.get_property('wel')
+        )
+
+    def get_predicate(self, field: 'FieldNode') -> str:
+        # TODO: make exporter promote this to an "else"?
+        return "1"
+
+    def get_assignments(self, field: 'FieldNode') -> List[str]:
+        field_path = self.get_field_path(field)
+
+        hwmask = field.get_property('hwmask')
+        hwenable = field.get_property('hwenable')
+        I = self.exp.hwif.get_input_identifier(field)
+        R = f"field_storage.{field_path}"
+        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 = self.exp.hwif.get_input_identifier(field)
+
+        return [
+            f"field_combo.{field_path}.next = {next_val};",
+            f"field_combo.{field_path}.load_next = '1;",
+        ]
+
+class WEWrite(AlwaysWrite):
+    comment = "HW Write - we"
+    def is_match(self, field: 'FieldNode') -> bool:
+        return (
+            field.is_hw_writable
+            and field.get_property('we')
+        )
+
+    def get_predicate(self, field: 'FieldNode') -> str:
+        prop = field.get_property('we')
+        if isinstance(prop, bool):
+            identifier = self.exp.hwif.get_implied_prop_input_identifier(field, "we")
+        else:
+            # signal or field
+            identifier = self.exp.dereferencer.get_value(prop)
+        return identifier
+
+class WELWrite(AlwaysWrite):
+    comment = "HW Write - wel"
+    def is_match(self, field: 'FieldNode') -> bool:
+        return (
+            field.is_hw_writable
+            and field.get_property('wel')
+        )
+
+    def get_predicate(self, field: 'FieldNode') -> str:
+        prop = field.get_property('wel')
+        if isinstance(prop, bool):
+            identifier = self.exp.hwif.get_implied_prop_input_identifier(field, "wel")
+        else:
+            # signal or field
+            identifier = self.exp.dereferencer.get_value(prop)
+        return f"!{identifier}"