From 09f2385282b0c98a3fdc4b89091d0c62b61725f5 Mon Sep 17 00:00:00 2001
From: Uri Shaked
Date: Wed, 2 Sep 2020 15:37:34 +0300
Subject: fix(interrupt): broken on ATmega2560

close #58
---
 src/cpu/interrupt.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'src/cpu/interrupt.ts')

diff --git a/src/cpu/interrupt.ts b/src/cpu/interrupt.ts
index 1c7d835..1bfa035 100644
--- a/src/cpu/interrupt.ts
+++ b/src/cpu/interrupt.ts
@@ -12,7 +12,10 @@ export function avrInterrupt(cpu: ICPU, addr: number) {
   const sp = cpu.dataView.getUint16(93, true);
   cpu.data[sp] = cpu.pc & 0xff;
   cpu.data[sp - 1] = (cpu.pc >> 8) & 0xff;
-  cpu.dataView.setUint16(93, sp - 2, true);
+  if (cpu.pc22Bits) {
+    cpu.data[sp - 2] = (cpu.pc >> 16) & 0xff;
+  }
+  cpu.dataView.setUint16(93, sp - (cpu.pc22Bits ? 3 : 2), true);
   cpu.data[95] &= 0x7f; // clear global interrupt flag
   cpu.cycles += 2;
   cpu.pc = addr;
-- 
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