From 32f102263bf28cd66a725d1f31379664809dbe9e Mon Sep 17 00:00:00 2001
From: Alex Mykyta <amykyta3@users.noreply.github.com>
Date: Mon, 7 Nov 2022 22:45:51 -0800
Subject: [PATCH] Fix misinterpretation of swacc behavior. Is asserted on both
 sw read and write. #21

---
 docs/props/field.rst                         |  6 +++---
 docs/props/rhs_props.rst                     |  4 ++--
 src/peakrdl_regblock/field_logic/__init__.py | 18 ++++++++++++++----
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/docs/props/field.rst b/docs/props/field.rst
index 7010f3d..93281d1 100644
--- a/docs/props/field.rst
+++ b/docs/props/field.rst
@@ -42,9 +42,9 @@ swacc
 ^^^^^
 |OK|
 
-If true, infers an output signal ``hwif_out..swacc`` that is asserted on the
-same clock cycle that the field is being sampled during a software read
-operation.
+If true, infers an output signal ``hwif_out..swacc`` that is asserted when
+accessed by software. Specifically, on the same clock cycle that the field is
+being sampled during a software read operation, or as it is being written.
 
 .. wavedrom::
 
diff --git a/docs/props/rhs_props.rst b/docs/props/rhs_props.rst
index 7e3dbc5..f9931f1 100644
--- a/docs/props/rhs_props.rst
+++ b/docs/props/rhs_props.rst
@@ -22,8 +22,8 @@ field -> swacc
 ^^^^^^^^^^^^^^
 |EX|
 
-Single-cycle strobe that indicates the field is being sampled during a software
-read operation.
+Single-cycle strobe that indicates the field is being accessed by software
+(read or write).
 
 
 field -> swmod
diff --git a/src/peakrdl_regblock/field_logic/__init__.py b/src/peakrdl_regblock/field_logic/__init__.py
index 346b74d..d1fb5ae 100644
--- a/src/peakrdl_regblock/field_logic/__init__.py
+++ b/src/peakrdl_regblock/field_logic/__init__.py
@@ -173,15 +173,25 @@ class FieldLogic:
 
     def get_swacc_identifier(self, field: 'FieldNode') -> str:
         """
-        Asserted when field is software accessed (read)
+        Asserted when field is software accessed (read or write)
         """
         buffer_reads = field.parent.get_property('buffer_reads')
-        if buffer_reads:
+        buffer_writes = field.parent.get_property('buffer_writes')
+        if buffer_reads and buffer_writes:
             rstrb = self.exp.read_buffering.get_trigger(field.parent)
-            return rstrb
+            wstrb = self.exp.write_buffering.get_write_strobe(field)
+            return f"{rstrb} || {wstrb}"
+        elif buffer_reads and not buffer_writes:
+            strb = self.exp.dereferencer.get_access_strobe(field)
+            rstrb = self.exp.read_buffering.get_trigger(field.parent)
+            return f"{rstrb} || ({strb} && decoded_req_is_wr)"
+        elif not buffer_reads and buffer_writes:
+            strb = self.exp.dereferencer.get_access_strobe(field)
+            wstrb = self.exp.write_buffering.get_write_strobe(field)
+            return f"{wstrb} || ({strb} && !decoded_req_is_wr)"
         else:
             strb = self.exp.dereferencer.get_access_strobe(field)
-            return f"{strb} && !decoded_req_is_wr"
+            return strb
 
     def get_swmod_identifier(self, field: 'FieldNode') -> str:
         """