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commodore64: work on 1541 VIA timer chips

This commit is contained in:
saxxonpike 2012-12-07 06:20:20 +00:00
parent e3082b206b
commit 28d0328a54
1 changed files with 189 additions and 1 deletions
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190
BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs
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@ -8,6 +8,61 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
// via
public class MOS6522 : Timer
{
private uint acrShiftMode;
private bool[] enableIrqCA;
private bool[] enableIrqCB;
private bool enableIrqSR;
private bool[] enableIrqT;
private bool[] irqCA;
private bool[] irqCB;
private bool irqSR;
private bool[] irqT;
private bool paLatchEnable;
private bool pbLatchEnable;
private uint[] pcrControlA;
private uint[] pcrControlB;
private byte sr;
private uint srControl;
private uint[] tControl;
public MOS6522()
{
enableIrqCA = new bool[2];
enableIrqCB = new bool[2];
enableIrqT = new bool[2];
irqCA = new bool[2];
irqCB = new bool[2];
irqT = new bool[2];
pcrControlA = new uint[2];
pcrControlB = new uint[2];
tControl = new uint[2];
}
public void HardReset()
{
acrShiftMode = 0;
enableIrqCA[0] = false;
enableIrqCA[1] = false;
enableIrqCB[0] = false;
enableIrqCB[1] = false;
enableIrqSR = false;
enableIrqT[0] = false;
enableIrqT[1] = false;
irqCA[0] = false;
irqCA[1] = false;
irqCB[0] = false;
irqCB[1] = false;
irqSR = false;
irqT[0] = false;
irqT[1] = false;
pcrControlA[0] = 0;
pcrControlA[1] = 0;
pcrControlB[0] = 0;
pcrControlB[1] = 0;
tControl[0] = 0;
tControl[1] = 0;
}
// ------------------------------------
public void ExecutePhase1()
@ -16,6 +71,10 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
public void ExecutePhase2()
{
pinIRQ = !(irqCA[0] | irqCA[1] |
irqCB[0] | irqCB[1] |
irqSR | irqT[0] | irqT[1]
);
}
// ------------------------------------
@ -44,8 +103,67 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
{
switch (addr)
{
case 0x0:
return ReadPortB();
case 0x1:
return ReadPortA();
case 0x2:
return ReadDirB();
case 0x3:
return ReadDirA();
case 0x4:
return (byte)(timer[0] & 0xFF);
case 0x5:
return (byte)(timer[0] >> 8);
case 0x6:
return (byte)(timerLatch[0] & 0xFF);
case 0x7:
return (byte)(timerLatch[0] >> 8);
case 0x8:
return (byte)(timer[1] & 0xFF);
case 0x9:
return (byte)(timer[1] >> 8);
case 0xA:
return sr;
case 0xB:
return (byte)(
(paLatchEnable ? 0x01 : 0x00) |
(pbLatchEnable ? 0x02 : 0x00) |
(byte)((srControl & 0x7) << 2) |
(byte)((tControl[1] & 0x1) << 5) |
(byte)((tControl[0] & 0x3) << 6)
);
case 0xC:
return (byte)(
(byte)(pcrControlA[0] & 0x1) |
(byte)((pcrControlA[1] & 0x3) << 1) |
(byte)((pcrControlB[0] & 0x1) << 4) |
(byte)((pcrControlB[1] & 0x3) << 5)
);
case 0xD:
return (byte)(
(irqCA[1] ? 0x01 : 0x00) |
(irqCA[0] ? 0x02 : 0x00) |
(irqSR ? 0x04 : 0x00) |
(irqCB[1] ? 0x08 : 0x00) |
(irqCB[0] ? 0x10 : 0x00) |
(irqT[1] ? 0x20 : 0x00) |
(irqT[0] ? 0x40 : 0x00) |
(pinIRQ ? 0x00 : 0x80)
);
case 0xE:
return (byte)(
(enableIrqCA[1] ? 0x01 : 0x00) |
(enableIrqCA[0] ? 0x02 : 0x00) |
(enableIrqSR ? 0x04 : 0x00) |
(enableIrqCB[1] ? 0x08 : 0x00) |
(enableIrqCB[0] ? 0x10 : 0x00) |
(enableIrqT[1] ? 0x20 : 0x00) |
(enableIrqT[0] ? 0x40 : 0x00) |
(0x80)
);
default:
return 0;
return 0x00;
}
}
@ -64,6 +182,76 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
{
switch (addr)
{
case 0x0:
WritePortB(val);
break;
case 0x1:
WritePortA(val);
break;
case 0x2:
WriteDirB(val);
break;
case 0x3:
WriteDirA(val);
break;
case 0x4:
timerLatch[0] &= 0xFF00;
timerLatch[0] |= val;
break;
case 0x5:
timerLatch[0] &= 0x00FF;
timerLatch[0] |= (uint)val << 8;
break;
case 0x6:
timerLatch[0] &= 0xFF00;
timerLatch[0] |= val;
break;
case 0x7:
timerLatch[0] &= 0x00FF;
timerLatch[0] |= (uint)val << 8;
break;
case 0x8:
timerLatch[1] &= 0xFF00;
timerLatch[1] |= val;
break;
case 0x9:
timerLatch[1] &= 0x00FF;
timerLatch[1] |= (uint)val << 8;
break;
case 0xA:
sr = val;
break;
case 0xB:
paLatchEnable = ((val & 0x01) != 0);
pbLatchEnable = ((val & 0x02) != 0);
srControl = (((uint)val >> 2) & 0x7);
tControl[1] = (((uint)val >> 5) & 0x1);
tControl[0] = (((uint)val >> 6) & 0x3);
break;
case 0xC:
pcrControlA[0] = (uint)(val & 0x1);
pcrControlA[1] = ((uint)val >> 1) & 0x7;
pcrControlB[0] = ((uint)val >> 4) & 0x1;
pcrControlB[1] = ((uint)val >> 5) & 0x7;
break;
case 0xD:
irqCA[1] = ((val & 0x01) != 0);
irqCA[0] = ((val & 0x02) != 0);
irqSR = ((val & 0x04) != 0);
irqCB[1] = ((val & 0x08) != 0);
irqCB[0] = ((val & 0x10) != 0);
irqT[1] = ((val & 0x20) != 0);
irqT[0] = ((val & 0x40) != 0);
break;
case 0xE:
enableIrqCA[1] = ((val & 0x01) != 0);
enableIrqCA[0] = ((val & 0x02) != 0);
enableIrqSR = ((val & 0x04) != 0);
enableIrqCB[1] = ((val & 0x08) != 0);
enableIrqCB[0] = ((val & 0x10) != 0);
enableIrqT[1] = ((val & 0x20) != 0);
enableIrqT[0] = ((val & 0x40) != 0);
break;
default:
break;
}