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z80dma: Implemented reset command

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This commit is contained in:
Angelo Salese 2009-09-18 11:59:16 +00:00
parent 77a3badd32
commit 2f246a1bee
1 changed files with 29 additions and 1 deletions
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30
src/emu/machine/z80dma.c
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@ -109,6 +109,7 @@ struct _z80dma_t
UINT8 rdy;
UINT8 irq_en;
UINT8 reset_pointer;
UINT8 is_read;
UINT8 cur_cycle;
@ -360,6 +361,7 @@ WRITE8_DEVICE_HANDLER( z80dma_w )
fatalerror("Unimplemented WR6 command %02x", data);
break;
case 0xA7: /* Initiate read sequence */
LOG(("Initiate Read Sequence\n"));
cntx->read_cur_follow = cntx->read_num_follow = 0;
if(READ_MASK(cntx) & 0x01) { cntx->read_regs_follow[cntx->read_num_follow++] = cntx->status; }
if(READ_MASK(cntx) & 0x02) { cntx->read_regs_follow[cntx->read_num_follow++] = BLOCKLEN_L(cntx); } //byte counter (low)
@ -371,6 +373,20 @@ WRITE8_DEVICE_HANDLER( z80dma_w )
break;
case 0xC3: /* Reset */
LOG(("Reset\n"));
cntx->dma_enabled = 0;
cntx->rdy = 1;
cntx->irq_en = 0;
/* Needs six reset commands to reset the DMA */
{
UINT8 WRi;
for(WRi=0;WRi<7;WRi++)
REG(cntx,WRi,cntx->reset_pointer) = 0;
cntx->reset_pointer++;
if(cntx->reset_pointer >= 6) { cntx->reset_pointer = 0; }
}
cntx->status = 0x38;
break;
case 0xCF: /* Load */
cntx->addressA = PORTA_ADDRESS(cntx);
@ -380,43 +396,54 @@ WRITE8_DEVICE_HANDLER( z80dma_w )
LOG(("Load A: %x B: %x N: %x\n", cntx->addressA, cntx->addressB, cntx->count));
break;
case 0x83: /* Disable dma */
LOG(("Disable DMA\n"));
cntx->dma_enabled = 0;
z80dma_rdy_w(device, 0, cntx->rdy);
break;
case 0x87: /* Enable dma */
LOG(("Enable DMA\n"));
cntx->dma_enabled = 1;
z80dma_rdy_w(device, 0, cntx->rdy);
break;
case 0xBB:
LOG(("Set Read Mask\n"));
cntx->regs_follow[cntx->num_follow++] = GET_REGNUM(cntx, READ_MASK(cntx));
break;
case 0xD3: /* Continue */
LOG(("Continue\n"));
cntx->count = 0;
cntx->dma_enabled = 1;
//"match not found" & "end of block" status flags zeroed here
cntx->status &= ~0x30;
break;
case 0xc7: /* Reset Port A Timing */
LOG(("Reset Port A Timing\n"));
PORTA_TIMING(cntx) = 0;
break;
case 0xcb: /* Reset Port B Timing */
LOG(("Reset Port B Timing\n"));
PORTB_TIMING(cntx) = 0;
break;
case 0xB3: /* Force ready */
LOG(("Force ready\n"));
cntx->rdy = (WR5(cntx) & 0x8)>>3;
z80dma_rdy_w(device, 0, cntx->rdy);
break;
case 0xAB: /* Enable interrupts */
LOG(("Enable IRQ\n"));
cntx->irq_en = 1;
break;
case 0xAF: /* Disable interrupts */
LOG(("Disable IRQ\n"));
cntx->irq_en = 0;
break;
case 0x8B: /* Reinitialize status byte */
/* FIXME: docs says these two is 1, but behaviour makes me think it's a 0, investigate */
LOG(("Reinitialize status byte\n"));
cntx->status &= ~0x30;
break;
case 0xFB:
LOG(("Z80DMA undocumented command triggered!\n"));
LOG(("Z80DMA undocumented command triggered 0x%02X!\n",data));
break;
default:
fatalerror("Unknown WR6 command %02x", data);
@ -537,6 +564,7 @@ static DEVICE_RESET( z80dma )
z80dma->dma_enabled = 0;
z80dma->read_num_follow = z80dma->read_cur_follow = 0;
z80dma->irq_en = 0;
z80dma->reset_pointer = 0;
z80dma_update_status(device);
}