bsnes/higan/gb/cartridge/mbc3/mbc3.cpp

121 lines
2.9 KiB
C++
Executable File

#ifdef CARTRIDGE_CPP
void Cartridge::MBC3::second() {
if(rtc_halt == false) {
if(++rtc_second >= 60) {
rtc_second = 0;
if(++rtc_minute >= 60) {
rtc_minute = 0;
if(++rtc_hour >= 24) {
rtc_hour = 0;
if(++rtc_day >= 512) {
rtc_day = 0;
rtc_day_carry = true;
}
}
}
}
}
}
uint8 Cartridge::MBC3::mmio_read(uint16 addr) {
if((addr & 0xc000) == 0x0000) { //$0000-3fff
return cartridge.rom_read(addr);
}
if((addr & 0xc000) == 0x4000) { //$4000-7fff
return cartridge.rom_read((rom_select << 14) | (addr & 0x3fff));
}
if((addr & 0xe000) == 0xa000) { //$a000-bfff
if(ram_enable) {
if(ram_select >= 0x00 && ram_select <= 0x03) {
return cartridge.ram_read((ram_select << 13) | (addr & 0x1fff));
}
if(ram_select == 0x08) return rtc_latch_second;
if(ram_select == 0x09) return rtc_latch_minute;
if(ram_select == 0x0a) return rtc_latch_hour;
if(ram_select == 0x0b) return rtc_latch_day;
if(ram_select == 0x0c) return (rtc_latch_day_carry << 7) | (rtc_latch_day >> 8);
}
return 0x00;
}
return 0x00;
}
void Cartridge::MBC3::mmio_write(uint16 addr, uint8 data) {
if((addr & 0xe000) == 0x0000) { //$0000-1fff
ram_enable = (data & 0x0f) == 0x0a;
return;
}
if((addr & 0xe000) == 0x2000) { //$2000-3fff
rom_select = (data & 0x7f) + ((data & 0x7f) == 0);
return;
}
if((addr & 0xe000) == 0x4000) { //$4000-5fff
ram_select = data;
return;
}
if((addr & 0xe000) == 0x6000) { //$6000-7fff
if(rtc_latch == 0 && data == 1) {
rtc_latch_second = rtc_second;
rtc_latch_minute = rtc_minute;
rtc_latch_hour = rtc_hour;
rtc_latch_day = rtc_day;
rtc_latch_day_carry = rtc_day_carry;
}
rtc_latch = data;
return;
}
if((addr & 0xe000) == 0xa000) { //$a000-bfff
if(ram_enable) {
if(ram_select >= 0x00 && ram_select <= 0x03) {
cartridge.ram_write((ram_select << 13) | (addr & 0x1fff), data);
} else if(ram_select == 0x08) {
if(data >= 60) data = 0;
rtc_second = data;
} else if(ram_select == 0x09) {
if(data >= 60) data = 0;
rtc_minute = data;
} else if(ram_select == 0x0a) {
if(data >= 24) data = 0;
rtc_hour = data;
} else if(ram_select == 0x0b) {
rtc_day = (rtc_day & 0x0100) | data;
} else if(ram_select == 0x0c) {
rtc_day = ((data & 1) << 8) | (rtc_day & 0xff);
rtc_halt = data & 0x40;
rtc_day_carry = data & 0x80;
}
}
return;
}
}
void Cartridge::MBC3::power() {
ram_enable = false;
rom_select = 0x01;
ram_select = 0x00;
rtc_latch = 0;
rtc_halt = true;
rtc_second = 0;
rtc_minute = 0;
rtc_hour = 0;
rtc_day = 0;
rtc_day_carry = false;
rtc_latch_second = 0;
rtc_latch_minute = 0;
rtc_latch_hour = 0;
rtc_latch_day = 0;
rtc_latch_day_carry = false;
}
#endif