ShuriZma
/
BizHawk
mirror of https://github.com/TASEmulators/BizHawk.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

C64: VIA PB7 output timing adjusted to match datasheet.

This commit is contained in:
SaxxonPike 2019-07-04 00:00:05 -05:00
parent cb48104d7a
commit e74dfe15a8
3 changed files with 35 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
BizHawk.Emulation.Cores/Computers/Commodore64/C64.MotherboardInterface.cs
View File

@ -18,43 +18,12 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64
return (Cpu.PortData & 0x20) != 0;
}
/*
private bool Cia0_ReadCnt()
{
return User.ReadCounter1() && Cia0.ReadCntBuffer();
}
private int Cia0_ReadPortA()
{
return cia0InputLatchA;
}
private int Cia0_ReadPortB()
{
return cia0InputLatchB;
}
private bool Cia0_ReadSP()
{
return User.ReadSerial1() && Cia0.ReadSpBuffer();
}
private bool Cia1_ReadSP()
{
return User.ReadSerial2() && Cia1.ReadSpBuffer();
}
private bool Cia1_ReadCnt()
{
return User.ReadCounter2() && Cia1.ReadCntBuffer();
}
*/
private int Cia1_ReadPortA()
{
// the low bits are actually the VIC memory address.
return (SerPort_ReadDataOut() && Serial.ReadDeviceData() ? 0x80 : 0x00) |
(SerPort_ReadClockOut() && Serial.ReadDeviceClock() ? 0x40 : 0x00);
(SerPort_ReadClockOut() && Serial.ReadDeviceClock() ? 0x40 : 0x00) |
0x3F;
}
private int Cia1_ReadPortB()

1
BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Via.Registers.cs
View File

@ -124,6 +124,7 @@
_t1C = _t1L;
_t1CLoaded = true;
_t1Delayed = 1;
_resetPb7NextClock = _acrT1Control == ACR_T1_CONTROL_INTERRUPT_ON_LOAD_AND_PULSE_PB7;
break;
case 0x7:
_t1L = (_t1L & 0xFF) | ((val & 0xFF) << 8);

35
BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Via.cs
View File

@ -29,6 +29,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
private const int ACR_T1_CONTROL_CONTINUOUS_INTERRUPTS = 0x40;
private const int ACR_T1_CONTROL_INTERRUPT_ON_LOAD_AND_ONESHOT_PB7 = 0x80;
private const int ACR_T1_CONTROL_CONTINUOUS_INTERRUPTS_AND_OUTPUT_ON_PB7 = 0xC0;
private const int ACR_T1_CONTROL_INTERRUPT_ON_LOAD_AND_PULSE_PB7 = 0x80;
private int _pra;
private int _ddra;
@ -66,6 +67,8 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
private bool _resetCa2NextClock;
private bool _resetCb2NextClock;
private bool _resetPb7NextClock;
private bool _setPb7NextClock;
private bool _handshakeCa2NextClock;
private bool _handshakeCb2NextClock;
@ -142,6 +145,8 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
_interruptNextClock = 0;
_t1CLoaded = false;
_t2CLoaded = false;
_resetPb7NextClock = false;
_setPb7NextClock = false;
}
public void ExecutePhase()
@ -150,7 +155,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
_ifr |= _interruptNextClock;
_interruptNextClock = 0;
// Process 'pulse' and 'handshake' outputs on CA2 and CB2
// Process 'pulse' and 'handshake' outputs on PB7, CA2 and CB2
if (_resetCa2NextClock)
{
Ca2 = true;
@ -174,6 +179,17 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
_resetCb2NextClock = _pcrCb2Control == PCR_CONTROL_PULSE_OUTPUT;
_handshakeCb2NextClock = false;
}
if (_resetPb7NextClock)
{
_prb &= 0x7F;
_resetPb7NextClock = false;
}
else if (_setPb7NextClock)
{
_prb |= 0x80;
_setPb7NextClock = false;
}
// Count timers
if (_t1Delayed > 0)
@ -183,7 +199,19 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
else
{
_t1C--;
if (_t1C < 0)
if (_t1C == 0)
{
switch (_acrT1Control)
{
case ACR_T1_CONTROL_CONTINUOUS_INTERRUPTS_AND_OUTPUT_ON_PB7:
_prb ^= 0x80;
break;
case ACR_T1_CONTROL_INTERRUPT_ON_LOAD_AND_PULSE_PB7:
_prb |= 0x80;
break;
}
}
else if (_t1C < 0)
{
if (_t1CLoaded)
{
@ -199,7 +227,6 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
break;
case ACR_T1_CONTROL_CONTINUOUS_INTERRUPTS_AND_OUTPUT_ON_PB7:
_t1C = _t1L;
_prb ^= 0x80;
_t1CLoaded = true;
break;
}
@ -399,6 +426,8 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
ser.Sync("T2Loaded", ref _t2CLoaded);
ser.Sync("T1Delayed", ref _t1Delayed);
ser.Sync("T2Delayed", ref _t2Delayed);
ser.Sync("ResetPb7NextClock", ref _resetPb7NextClock);
ser.Sync("SetPb7NextClock", ref _setPb7NextClock);
}
}
}