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Implemented 16-bit DMA support for GUS.

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This commit is contained in:
SarahW 2017-06-16 20:46:11 +01:00
commit 69f0f7b01c
1 changed files with 35 additions and 9 deletions
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44
src/sound_gus.c
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@ -380,13 +380,27 @@ gus->curx[gus->voice]=(gus->curx[gus->voice]&0xFFF8000)|((val&0x7F)<<8);
while (c<65536)
{
int dma_result;
d = gus->ram[gus->dmaaddr];
if (val & 0x80) d ^= 0x80;
dma_result = dma_channel_write(gus->dma, d);
if (dma_result == DMA_NODATA)
break;
if (val & 0x04)
{
uint32_t gus_addr = (gus->dmaaddr & 0xc0000) | ((gus->dmaaddr & 0x1ffff) << 1);
d = gus->ram[gus_addr] | (gus->ram[gus_addr + 1] << 8);
if (val & 0x80)
d ^= 0x8080;
dma_result = dma_channel_write(gus->dma, d);
if (dma_result == DMA_NODATA)
break;
}
else
{
d = gus->ram[gus->dmaaddr];
if (val & 0x80)
d ^= 0x80;
dma_result = dma_channel_write(gus->dma, d);
if (dma_result == DMA_NODATA)
break;
}
gus->dmaaddr++;
gus->dmaaddr&=0xFFFFF;
gus->dmaaddr &= 0xFFFFF;
c++;
if (dma_result & DMA_OVER)
break;
@ -403,10 +417,22 @@ gus->curx[gus->voice]=(gus->curx[gus->voice]&0xFFF8000)|((val&0x7F)<<8);
d = dma_channel_read(gus->dma);
if (d == DMA_NODATA)
break;
if (val&0x80) d^=0x80;
gus->ram[gus->dmaaddr]=d;
if (val & 0x04)
{
uint32_t gus_addr = (gus->dmaaddr & 0xc0000) | ((gus->dmaaddr & 0x1ffff) << 1);
if (val & 0x80)
d ^= 0x8080;
gus->ram[gus_addr] = d & 0xff;
gus->ram[gus_addr +1] = (d >> 8) & 0xff;
}
else
{
if (val & 0x80)
d ^= 0x80;
gus->ram[gus->dmaaddr] = d;
}
gus->dmaaddr++;
gus->dmaaddr&=0xFFFFF;
gus->dmaaddr &= 0xFFFFF;
c++;
if (d & DMA_OVER)
break;