From e59bd9654aa92b50301db0097c768363153ab5e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Mon, 4 Jul 2022 00:28:58 +0100
Subject: [PATCH] feat: new ret instruction
---
src/inst.rs | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/inst.rs b/src/inst.rs
index 2ddc8412..05c7735b 100644
--- a/src/inst.rs
+++ b/src/inst.rs
@@ -231,7 +231,7 @@ pub const INSTRUCTIONS: [(fn(&mut Cpu), u8, &'static str); 256] = [
(push_de, 16, "PUSH DE"),
(sub_a_u8, 8, "SUB A, u8"),
(noimpl, 4, "! UNIMP !"),
- (noimpl, 4, "! UNIMP !"),
+ (ret_c, 8, "RET C"),
(reti, 16, "RETI"),
(jp_c_u16, 12, "JP C, u16"),
(illegal, 4, "ILLEGAL"),
@@ -1450,6 +1450,15 @@ fn sub_a_u8(cpu: &mut Cpu) {
cpu.a = sub_set_flags(cpu, cpu.a, byte);
}
+fn ret_c(cpu: &mut Cpu) {
+ if !cpu.get_carry() {
+ return;
+ }
+
+ cpu.pc = cpu.pop_word();
+ cpu.ticks = cpu.ticks.wrapping_add(12);
+}
+
fn reti(cpu: &mut Cpu) {
cpu.pc = cpu.pop_word();
cpu.enable_int();
--
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