AxibugEmuOnline/References/VirtuaNESex_src_191105/NES/Mapper/Mapper017.cpp
2024-08-05 17:58:53 +08:00

94 lines
1.8 KiB
C++

//////////////////////////////////////////////////////////////////////////
// Mapper017 FFE F8xxx //
//////////////////////////////////////////////////////////////////////////
void Mapper017::Reset()
{
SetPROM_32K_Bank( 0, 1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );
if( VROM_1K_SIZE ) {
SetVROM_8K_Bank( 0 );
}
irq_enable = 0;
irq_counter = 0;
irq_latch = 0;
}
void Mapper017::WriteLow( WORD addr, BYTE data )
{
switch( addr ) {
case 0x42FE:
if( data&0x10 ) SetVRAM_Mirror( VRAM_MIRROR4H );
else SetVRAM_Mirror( VRAM_MIRROR4L );
break;
case 0x42FF:
if( data&0x10 ) SetVRAM_Mirror( VRAM_HMIRROR );
else SetVRAM_Mirror( VRAM_VMIRROR );
break;
case 0x4501:
irq_enable = 0;
nes->cpu->ClrIRQ( IRQ_MAPPER );
break;
case 0x4502:
irq_latch = (irq_latch&0xFF00)|data;
break;
case 0x4503:
irq_latch = (irq_latch&0x00FF)|((INT)data<<8);
irq_counter = irq_latch;
irq_enable = 0xFF;
break;
case 0x4504:
case 0x4505:
case 0x4506:
case 0x4507:
SetPROM_8K_Bank( addr&0x07, data );
break;
case 0x4510:
case 0x4511:
case 0x4512:
case 0x4513:
case 0x4514:
case 0x4515:
case 0x4516:
case 0x4517:
SetVROM_1K_Bank( addr&0x07, data );
break;
default:
Mapper::WriteLow( addr, data );
break;
}
}
void Mapper017::HSync( INT scanline )
{
if( irq_enable ) {
if( irq_counter >= 0xFFFF-113 ) {
nes->cpu->SetIRQ( IRQ_MAPPER );
// nes->cpu->IRQ();
// irq_counter = 0;
// irq_enable = 0;
irq_counter &= 0xFFFF;
} else {
irq_counter += 113;
}
}
}
void Mapper017::SaveState( LPBYTE p )
{
p[0] = irq_enable;
*(INT*)&p[1] = irq_counter;
*(INT*)&p[5] = irq_latch;
}
void Mapper017::LoadState( LPBYTE p )
{
irq_enable = p[0];
irq_counter = *(INT*)&p[1];
irq_latch = *(INT*)&p[5];
}