From 520f37156074212a1a73bfa0548fe693e2859b59 Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Mon, 17 Nov 2025 23:00:40 +0100
Subject: [PATCH] com2w: added support for pin change interrupts on atmega644P

---
 avr/modules/com2w/com2w.asm | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/avr/modules/com2w/com2w.asm b/avr/modules/com2w/com2w.asm
index e94b648..d084afa 100644
--- a/avr/modules/com2w/com2w.asm
+++ b/avr/modules/com2w/com2w.asm
@@ -70,6 +70,20 @@
 
 
 
+.macro M_COM2WSETUPPCICR
+  inr r16, COM_IRQ_ADDR_CLK               ; enable pin change irq for CLK line
+  ori r16, (1<<COM_IRQ_BIT_CLK)
+  outr COM_IRQ_ADDR_CLK, r16
+
+  inr r16, COM_IRQ_ICR_ADDR               ; enable pin change irq in PCICR
+  ori r16, (1<<COM_IRQ_ICR_BIT)
+  outr COM_IRQ_ICR_ADDR, R16
+  ldi r16, (1<<COM_IRQ_IFR_BIT)           ; clear pending irq by writing 1 to CLK bit
+  out COM_IRQ_IFR_ADDR, r16
+.endmacro
+
+
+
 
 
 .dseg
@@ -116,14 +130,18 @@ COM2W_Init:
   rcall com2wEnableClkIrq
 
   ; enable IRQ
-.ifdef INT0
-  .if COM_IRQ_BIT_CLK == INT0
-    M_COM2WSETUPINT0
+.ifdef COM_IRQ_ICR_ADDR
+  M_COM2WSETUPPCICR
+.else
+  .ifdef INT0
+    .if COM_IRQ_BIT_CLK == INT0
+      M_COM2WSETUPINT0
+    .else
+      M_COM2WSETUPPCI
+    .endif
   .else
     M_COM2WSETUPPCI
   .endif
-.else
-  M_COM2WSETUPPCI
 .endif