From 19babd325a5cd742d47348fce8b7452b32c14e6d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Sat, 2 Jul 2022 09:58:56 +0100
Subject: [PATCH] fix half carry in sub
---
src/cpu.rs | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)
diff --git a/src/cpu.rs b/src/cpu.rs
index 4ad39386..a56d2de9 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -538,6 +538,13 @@ impl Cpu {
println!("GOING TO PLAY BOOT SOUND");
}
+ if pc == 0x008f {
+ println!("GOING TO PLAY BOOT 0x00e0");
+ }
+
+ // calls the current instruction and increments the number of
+ // cycles executed by the instruction time of the instruction
+ // that has just been executed
instruction_fn(self);
self.ticks = self.ticks.wrapping_add(*instruction_time as u32);
@@ -738,11 +745,12 @@ fn inc_b(cpu: &mut Cpu) {
}
fn dec_b(cpu: &mut Cpu) {
- let value = cpu.b.wrapping_sub(1);
+ let b = cpu.b;
+ let value = b.wrapping_sub(1);
cpu.set_sub(true);
cpu.set_zero(value == 0);
- cpu.set_half_carry((value & 0xf) == 0xf);
+ cpu.set_half_carry((b & 0xf) == 0xf);
cpu.b = value;
}
@@ -785,11 +793,12 @@ fn inc_c(cpu: &mut Cpu) {
}
fn dec_c(cpu: &mut Cpu) {
- let value = cpu.c.wrapping_sub(1);
+ let c = cpu.c;
+ let value = c.wrapping_sub(1);
cpu.set_sub(true);
cpu.set_zero(value == 0);
- cpu.set_half_carry((value & 0xf) == 0xf);
+ cpu.set_half_carry((c & 0xf) == 0xf);
cpu.c = value;
}
@@ -809,11 +818,12 @@ fn inc_de(cpu: &mut Cpu) {
}
fn dec_d(cpu: &mut Cpu) {
- let value = cpu.d.wrapping_sub(1);
+ let d = cpu.d;
+ let value = d.wrapping_sub(1);
cpu.set_sub(true);
cpu.set_zero(value == 0);
- cpu.set_half_carry((value & 0xf) == 0xf);
+ cpu.set_half_carry((d & 0xf) == 0xf);
cpu.d = value;
}
@@ -841,11 +851,12 @@ fn ld_a_mde(cpu: &mut Cpu) {
}
fn dec_e(cpu: &mut Cpu) {
- let value = cpu.e.wrapping_sub(1);
+ let e = cpu.e;
+ let value = e.wrapping_sub(1);
cpu.set_sub(true);
cpu.set_zero(value == 0);
- cpu.set_half_carry((value & 0xf) == 0xf);
+ cpu.set_half_carry((e & 0xf) == 0xf);
cpu.e = value;
}
@@ -916,11 +927,12 @@ fn ld_mhld_a(cpu: &mut Cpu) {
}
fn dec_a(cpu: &mut Cpu) {
- let value = cpu.a.wrapping_sub(1);
+ let a = cpu.a;
+ let value = a.wrapping_sub(1);
cpu.set_sub(true);
cpu.set_zero(value == 0);
- cpu.set_half_carry((value & 0xf) == 0xf);
+ cpu.set_half_carry((a & 0xf) == 0xf);
cpu.a = value;
}
--
GitLab