HDMA accuracy improvement

This commit is contained in:
Lior Halphon 2016-06-18 16:51:25 +03:00
parent d58ddef07b
commit 64832e0e9e
1 changed files with 4 additions and 0 deletions

View File

@ -461,6 +461,10 @@ static void write_high_memory(GB_gameboy_t *gb, unsigned short addr, unsigned ch
gb->hdma_current_src = (gb->io_registers[GB_IO_HDMA1] << 8) | (gb->io_registers[GB_IO_HDMA2] & 0xF0);
gb->hdma_current_dest = (gb->io_registers[GB_IO_HDMA3] << 8) | (gb->io_registers[GB_IO_HDMA4] & 0xF0);
gb->hdma_steps_left = (gb->io_registers[GB_IO_HDMA5] & 0x7F) + 1;
/* Todo: Verify this. Gambatte's DMA tests require this. */
if (gb->hdma_current_dest + (gb->hdma_steps_left << 4) > 0xFFFF) {
gb->hdma_steps_left = (0x10000 - gb->hdma_current_dest) >> 4;
}
gb->hdma_cycles = 0;
return;