Initial Commit - Forked from PeakRDL-regblock @ a440cc19769069be831d267505da4f3789a26695

src/peakrdl_regblock/field_logic/sw_onwrite.py

@@ -0,0 +1,129 @@
+from typing import TYPE_CHECKING, List, Optional
+
+from systemrdl.rdltypes import OnWriteType
+
+from .bases import NextStateConditional
+
+if TYPE_CHECKING:
+    from systemrdl.node import FieldNode
+
+# TODO: implement sw=w1 "write once" fields
+
+class _OnWrite(NextStateConditional):
+    onwritetype: Optional[OnWriteType] = None
+    def is_match(self, field: 'FieldNode') -> bool:
+        return field.is_sw_writable and field.get_property('onwrite') == self.onwritetype
+
+    def get_predicate(self, field: 'FieldNode') -> str:
+        if field.parent.get_property('buffer_writes'):
+            # Is buffered write. Use alternate strobe
+            wstrb = self.exp.write_buffering.get_write_strobe(field)
+
+            if field.get_property('swwe') or field.get_property('swwel'):
+                # dereferencer will wrap swwel complement if necessary
+                qualifier = self.exp.dereferencer.get_field_propref_value(field, 'swwe')
+                return f"{wstrb} && {qualifier}"
+
+            return wstrb
+        else:
+            # is regular register
+            strb = self.exp.dereferencer.get_access_strobe(field)
+
+            if field.get_property('swwe') or field.get_property('swwel'):
+                # dereferencer will wrap swwel complement if necessary
+                qualifier = self.exp.dereferencer.get_field_propref_value(field, 'swwe')
+                return f"{strb} && decoded_req_is_wr && {qualifier}"
+
+            return f"{strb} && decoded_req_is_wr"
+
+    def get_assignments(self, field: 'FieldNode') -> List[str]:
+        accesswidth = field.parent.get_property("accesswidth")
+
+        # Due to 10.6.1-f, it is impossible for a field with an onwrite action to
+        # be split across subwords.
+        # Therefore it is ok to get the subword idx from only one of the bit offsets
+        sidx = field.low // accesswidth
+
+        # field does not get split between subwords
+        R = self.exp.field_logic.get_storage_identifier(field)
+        D = self.exp.field_logic.get_wr_data(field, sidx)
+        S = self.exp.field_logic.get_wr_biten(field, sidx)
+        lines = [
+            f"next_c = {self.get_onwrite_rhs(R, D, S)};",
+            "load_next_c = '1;",
+        ]
+        return lines
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        raise NotImplementedError
+
+
+#-------------------------------------------------------------------------------
+class WriteOneSet(_OnWrite):
+    comment = "SW write 1 set"
+    onwritetype = OnWriteType.woset
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        return f"{reg} | ({data} & {strb})"
+
+class WriteOneClear(_OnWrite):
+    comment = "SW write 1 clear"
+    onwritetype = OnWriteType.woclr
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        return f"{reg} & ~({data} & {strb})"
+
+class WriteOneToggle(_OnWrite):
+    comment = "SW write 1 toggle"
+    onwritetype = OnWriteType.wot
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        return f"{reg} ^ ({data} & {strb})"
+
+class WriteZeroSet(_OnWrite):
+    comment = "SW write 0 set"
+    onwritetype = OnWriteType.wzs
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        return f"{reg} | (~{data} & {strb})"
+
+class WriteZeroClear(_OnWrite):
+    comment = "SW write 0 clear"
+    onwritetype = OnWriteType.wzc
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        return f"{reg} & ({data} | ~{strb})"
+
+class WriteZeroToggle(_OnWrite):
+    comment = "SW write 0 toggle"
+    onwritetype = OnWriteType.wzt
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        return f"{reg} ^ (~{data} & {strb})"
+
+class WriteClear(_OnWrite):
+    comment = "SW write clear"
+    onwritetype = OnWriteType.wclr
+
+    def get_assignments(self, field: 'FieldNode') -> List[str]:
+        return [
+            "next_c = '0;",
+            "load_next_c = '1;",
+        ]
+
+class WriteSet(_OnWrite):
+    comment = "SW write set"
+    onwritetype = OnWriteType.wset
+
+    def get_assignments(self, field: 'FieldNode') -> List[str]:
+        return [
+            "next_c = '1;",
+            "load_next_c = '1;",
+        ]
+
+class Write(_OnWrite):
+    comment = "SW write"
+    onwritetype = None
+
+    def get_onwrite_rhs(self, reg: str, data: str, strb: str) -> str:
+        return f"({reg} & ~{strb}) | ({data} & {strb})"