More accurate pausing behavior, including revision differences
@@ -474,7 +474,8 @@ void GB_apu_run(GB_gameboy_t *gb)
gb->apu.noise_channel.alignment += cycles;
if (gb->apu.square_sweep_calculate_countdown &&
- ((gb->io_registers[GB_IO_NR10] & 7) || gb->apu.square_sweep_calculate_countdown <= 7)) { // Calculation is paused if the lower bits
+ ((gb->io_registers[GB_IO_NR10] & 7) ||
+ gb->apu.square_sweep_calculate_countdown <= (gb->model > GB_MODEL_CGB_C? 3 : 1))) { // Calculation is paused if the lower bits
if (gb->apu.square_sweep_calculate_countdown > cycles) {
gb->apu.square_sweep_calculate_countdown -= cycles;
}
@@ -823,7 +824,10 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
gb->apu.shadow_sweep_sample_length = 0;
if (gb->io_registers[GB_IO_NR10] & 7) {
/* APU bug: if shift is nonzero, overflow check also occurs on trigger */
- gb->apu.square_sweep_calculate_countdown = (gb->io_registers[GB_IO_NR10] & 0x7) * 2 + 7 - gb->apu.lf_div;
+ gb->apu.square_sweep_calculate_countdown = (gb->io_registers[GB_IO_NR10] & 0x7) * 2 + 5 - gb->apu.lf_div;
+ if (gb->model > GB_MODEL_CGB_C) {
+ gb->apu.square_sweep_calculate_countdown += 2;
+ }
gb->apu.sweep_length_addend = gb->apu.square_channels[GB_SQUARE_1].sample_length;
gb->apu.sweep_length_addend >>= (gb->io_registers[GB_IO_NR10] & 7);
}
