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working on mooneye test suite

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This commit is contained in:
Samuel Walker
2025-05-30 00:35:44 -06:00
parent 4d6973304d
commit 1f55455a65
7 changed files with 87 additions and 44 deletions
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74
lib/timer.c
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@ -5,40 +5,58 @@
static timer_context ctx = {0};
bool selected_bit() {
switch(ctx.tac & 0b11) {
case 0b00:
return (ctx.div & (1 << 9));
break;
case 0b01:
return (ctx.div & (1 << 3));
break;
case 0b10:
return (ctx.div & (1 << 5));
break;
case 0b11:
return (ctx.div & (1 << 7));
break;
}
}
void inc_tima() {
ctx.tima++;
if(ctx.tima == 0x00){
ctx.tima_needs_reset = true;
}
}
void timer_init() {
ctx.div = 0XAC00;
}
void timer_tick() {
u16 prev_div = ctx.div;
bool old = selected_bit();
ctx.div++;
bool timer_update = false;
switch(ctx.tac & 0b11) {
case 0b00:
timer_update = (prev_div & (1 << 9)) && (!(ctx.div & (1 << 9)));
break;
bool new = selected_bit();
case 0b01:
timer_update = (prev_div & (1 << 3)) && (!(ctx.div & (1 << 3)));
break;
case 0b10:
timer_update = (prev_div & (1 << 5)) && (!(ctx.div & (1 << 5)));
break;
case 0b11:
timer_update = (prev_div & (1 << 7)) && (!(ctx.div & (1 << 7)));
break;
}
if(timer_update && ctx.tac & (1 << 2)) {
ctx.tima++;
if(ctx.tima == 0xFF){
if((prev_div & (1 << 1)) && (!(ctx.div & (1 << 1)))){
if(ctx.tima_just_reset)
ctx.tima_just_reset = false;
if(ctx.tima_needs_reset){
ctx.tima = ctx.tma;
ctx.tima_needs_reset = false;
ctx.tima_just_reset = true;
cpu_request_interrupt(IT_TIMER);
}
}
if(ctx.tac & 0b100 && old && !new) {
inc_tima();
}
audio_sample_tick();
if((prev_div & (1 << 12)) && (!(ctx.div & (1 << 12)))){
@ -54,22 +72,36 @@ void timer_write(u16 address, u8 value){
switch(address) {
case 0xFF04:
//DIV
if(selected_bit()) {
inc_tima();
}
ctx.div = 0;
break;
case 0xFF05:
//TIMA
if(ctx.tima_just_reset)
return;
ctx.tima_needs_reset = false;
ctx.tima = value;
break;
case 0xFF06:
//TMA
if(ctx.tima_just_reset)
ctx.tima = value;
ctx.tma = value;
break;
case 0xFF07:
//TAC
bool current = selected_bit();
bool old_enable = ctx.tac & 0b100;
ctx.tac = value;
bool new = selected_bit();
if(((current && !new) && (ctx.tac & 0b100)) || (current && old_enable && !(ctx.tac & 0b100))) {
inc_tima();
}
break;
}
}