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GBHawk: make timer <> cpu loop interaction consistent

This commit is contained in:
alyosha-tas 2020-08-19 11:58:06 -04:00
parent 96fa21e238
commit 6e8362eef0
4 changed files with 46 additions and 31 deletions
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2
src/BizHawk.Emulation.Cores/CPUs/LR35902/LR35902.cs
View File

@ -462,7 +462,7 @@ namespace BizHawk.Emulation.Cores.Components.LR35902
break;
}
if (stop_time == (32768 - 2))
if (stop_time == (32769))
{
SpeedFunc(1);
}

18
src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Audio.cs
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@ -896,25 +896,29 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
}
}
}
timer_bit_old = Core.double_speed ? Core.timer.divider_reg.Bit(13) : Core.timer.divider_reg.Bit(12);
if (sequencer_reset_cd > 0)
{
sequencer_reset_cd--;
if (sequencer_reset_cd == 0)
{
// seems to be off by one issues here, hard to tell since the write takes place in the cpu loop
// but the effect takes place in the sound loop
if (Core.double_speed)
{
sequencer_len = Core.timer.divider_reg.Bit(13) ? 0 : 1;
sequencer_vol = Core.timer.divider_reg.Bit(13) ? 0 : 1;
sequencer_swp = Core.timer.divider_reg.Bit(13) ? 0 : 1;
sequencer_len = (Core.timer.divider_reg - 1).Bit(13) ? 0 : 1;
sequencer_vol = (Core.timer.divider_reg - 1).Bit(13) ? 0 : 1;
sequencer_swp = (Core.timer.divider_reg - 1).Bit(13) ? 0 : 1;
}
else
{
sequencer_len = Core.timer.divider_reg.Bit(12) ? 0 : 1;
sequencer_vol = Core.timer.divider_reg.Bit(12) ? 0 : 1;
sequencer_swp = Core.timer.divider_reg.Bit(12) ? 0 : 1;
sequencer_len = (Core.timer.divider_reg + 1).Bit(12) ? 0 : 1;
sequencer_vol = (Core.timer.divider_reg + 1).Bit(12) ? 0 : 1;
sequencer_swp = (Core.timer.divider_reg + 1).Bit(12) ? 0 : 1;
}
}
}

37
src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBHawk.IEmulator.cs
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@ -108,28 +108,34 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
{
if (ppu.DMA_start && !cpu.halted && !cpu.stopped) { ppu.DMA_tick(); }
serialport.serial_transfer_tick();
cpu.ExecuteOne();
timer.tick();
cpu.ExecuteOne();
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
}
if (ppu.DMA_start && !cpu.halted && !cpu.stopped) { ppu.DMA_tick(); }
serialport.serial_transfer_tick();
cpu.ExecuteOne();
timer.tick();
cpu.ExecuteOne();
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
}
else
{
if (double_speed)
{
cpu.TotalExecutedCycles++;
timer.tick();
cpu.TotalExecutedCycles++;
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
}
cpu.TotalExecutedCycles++;
timer.tick();
cpu.TotalExecutedCycles++;
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
}
@ -190,29 +196,37 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
// These things all tick twice as fast in GBC double speed mode
if (ppu.DMA_start && !cpu.halted && !cpu.stopped) { ppu.DMA_tick(); }
serialport.serial_transfer_tick();
cpu.ExecuteOne();
timer.tick();
cpu.ExecuteOne();
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
if (double_speed)
{
if (ppu.DMA_start && !cpu.halted && !cpu.stopped) { ppu.DMA_tick(); }
serialport.serial_transfer_tick();
cpu.ExecuteOne();
timer.tick();
cpu.ExecuteOne();
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
}
}
else
{
cpu.TotalExecutedCycles++;
timer.tick();
cpu.TotalExecutedCycles++;
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
if (double_speed)
{
cpu.TotalExecutedCycles++;
timer.tick();
cpu.TotalExecutedCycles++;
timer.divider_reg++;
if (delays_to_process) { process_delays(); }
}
}
@ -286,9 +300,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
speed_switch = false;
Console.WriteLine("Speed Switch: " + cpu.TotalExecutedCycles);
// reset the divider (only way for speed_change_timing_fine.gbc and speed_change_cancel.gbc to both work)
timer.divider_reg = 0;
int ret = double_speed ? 32769 : 32769; // actual time needs checking
return ret;
}
@ -302,6 +313,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
}
else
{
// reset the divider (only way for speed_change_timing_fine.gbc and speed_change_cancel.gbc to both work)
timer.divider_reg = 1;
double_speed = !double_speed;
return 0;
}
@ -330,7 +343,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
public void SetIntRegs(byte r)
{
if (((REG_FF0F & 4) == 4) && ((r & 4) == 0) && is_GBC) { timer.IRQ_block = true; }
if (((REG_FF0F & 4) == 4) && ((r & 4) == 0) && timer.IRQ_block && !is_GBC) { r |= 4; }
REG_FF0F = r;
}

20
src/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Timer.cs
View File

@ -41,7 +41,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
switch (addr)
{
case 0xFF04: ret = (byte)(divider_reg >> 8); break; // DIV register
case 0xFF04: ret = (byte)(divider_reg >> 8); break; // DIV register
case 0xFF05: ret = timer; break; // TIMA (Timer Counter)
case 0xFF06: ret = timer_reload; break; // TMA (Timer Modulo)
case 0xFF07: ret = timer_control; break; // TAC (Timer Control)
@ -56,6 +56,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
{
// DIV register
case 0xFF04:
// NOTE: even though there is an automatic increment directly after the CPU loop,
// it is still expected that 0 is written here
divider_reg = 0;
break;
@ -143,8 +145,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
public void tick()
{
divider_reg++;
IRQ_block = false;
// pick a bit to test based on the current value of timer control
switch (timer_control & 3)
{
@ -201,20 +203,16 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
next_free_cycle = 4 + Core.cpu.TotalExecutedCycles;
// set interrupts
if (!IRQ_block)
{
if (Core.REG_FFFF.Bit(2)) { Core.cpu.FlagI = true; }
Core.REG_FF0F |= 0x04;
}
if (Core.REG_FFFF.Bit(2)) { Core.cpu.FlagI = true; }
Core.REG_FF0F |= 0x04;
IRQ_block = true;
}
}
IRQ_block = false;
}
public void Reset()
{
divider_reg = (ushort)(Core.is_GBC ? 0xFFFF : 0x1);
divider_reg = (ushort)(Core.is_GBC ? 0xFFFE : 0xFFFE);
timer_reload = 0;
timer = 0;
timer_old = 0;