void ws_timer_count(int Cycles)
{
int i;
for (i=0; i<TOTAL_TIMER; i++)
{
if (ws_timer[i] > 0)
{
ws_timer[i] -= Cycles;
if (ws_timer[i] <= 0)
{
switch (i)
{
case 0: // HBlank Timer
if ((ws_ioRam[0xb2]&0x80) && ws_ioRam[0xa4])
{
if (!ws_ioRam[0xa5])
ws_ioRam[0xa5] = ws_ioRam[0xa4];
if (ws_ioRam[0xa5])
ws_ioRam[0xa5]--;
if (!ws_ioRam[0xa5])
{
ws_ioRam[0xb6] |= 0x80;
nec_int();
}
}
ws_audio_process();
ws_timer[0] += 256;
break;
case 1: // VBlank
if (ws_ioRam[0xb2]&0x40)
{
ws_ioRam[0xb6] |= 0x40;
nec_int();
}
ws_timer[1] += 256*159;
break;
case 2: // SoundDMA
ws_audio_sounddma();
break;
}
}
}
}
}
// Executes one scanline (256 CPU cycles)
bool wsExecuteLine()
{
bool frameFin = false;
// Update scanline register
ioPort[0x02] = gpuCurScanline;
// Execute NEC CPU core
// Hblank : 256 CPU cycles
nec_execute(256);
// Update BG color to background color
*(u16*)0x05000000 = *((u16*)0x05000000 + ioPort[0x01]);
// Increase scanline and check for Vertical Blank
if(++gpuCurScanline == 144)
frameFin = true;
// Vblank : 159 Hblank = 159*256/3072000 = 75.47 Hz
if(gpuCurScanline > 158) {
gpuCurScanline = 0;
// VBlank End IRQ
if((ioPort[0xB2] & BIT(5))) {
// ?!
if(ioPort[0xA7] != 0x35) {
// Clear IRQ Flag
ioPort[0xB6] &= ~BIT(5);
// Exec IRQ
nec_int((ioPort[0xB0] + 5) << 2);
}
}
}
ioPort[0x02] = gpuCurScanline;
// VBlank IRQ
if(frameFin) {
if(ioPort[0xB2] & BIT(6)) {
// Clear IRQ Flag
ioPort[0xB6] &= ~BIT(6);
// Exec IRQ
nec_int((ioPort[0xB0] + 6) << 2);
}
}
// HBlank IRQ
if(ioPort[0xA4] && (ioPort[0xb2] & BIT(7))) {
if(!ioPort[0xA5])
ioPort[0xA5] = ioPort[0xA4];
if(ioPort[0xA5])
--ioPort[0xA5];
// HBlank IRQ Active?
if(!ioPort[0xA5] && (ioPort[0xB2] & BIT(7))) {
// Clear IRQ Flag
ioPort[0xB6] &= ~BIT(7);
// Exec IRQ
nec_int((ioPort[0xB0] + 7) << 2);
}
}
// Hblank Timer IRQ
if((ioPort[0x02] == ioPort[0x03]) && (ioPort[0xb2] & BIT(4))) {
// Clear IRQ Flag
ioPort[0xb6] &= ~BIT(4);
// Exec IRQ
nec_int((ioPort[0xB0] + 4) << 2);
}
// Is frame finished?
return frameFin;
}
