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z80dma: added preliminary search mode support and fixed a bug with WR3 mask byte writes

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This commit is contained in:
Angelo Salese 2009-09-21 17:07:31 +00:00
parent fcf9e90cd5
commit b6e43d1bfd
1 changed files with 21 additions and 8 deletions
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29
src/emu/machine/z80dma.c
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@ -83,6 +83,11 @@
#define PORTB_IS_SOURCE(_c) (!PORTA_IS_SOURCE(_c))
#define TRANSFER_MODE(_c) (WR0(_c) & 0x03)
#define MATCH_F_SET(_c) (_c->status &= ~0x10)
#define MATCH_F_CLEAR(_c) (_c->status |= 0x10)
#define EOB_F_SET(_c) (_c->status &= ~0x20)
#define EOB_F_CLEAR(_c) (_c->status |= 0x20)
#define TM_TRANSFER (0x01)
#define TM_SEARCH (0x02)
#define TM_SEARCH_TRANSFER (0x03)
@ -138,6 +143,7 @@ static void z80dma_do_read(const device_config *device)
mode = TRANSFER_MODE(cntx);
switch(mode) {
case TM_TRANSFER:
case TM_SEARCH:
if (PORTA_IS_SOURCE(cntx))
{
if (PORTA_MEMORY(cntx))
@ -157,9 +163,6 @@ static void z80dma_do_read(const device_config *device)
cntx->addressB += PORTB_FIXED(cntx) ? 0 : PORTB_INC(cntx) ? PORTB_STEP(cntx) : -PORTB_STEP(cntx);
}
break;
case TM_SEARCH:
fatalerror("z80dma_do_operation: unhandled search mode!\n");
break;
case TM_SEARCH_TRANSFER:
fatalerror("z80dma_do_operation: unhandled search & transfer mode !\n");
break;
@ -205,7 +208,17 @@ static int z80dma_do_write(const device_config *device)
break;
case TM_SEARCH:
fatalerror("z80dma_do_operation: unhandled search mode!\n");
{
UINT8 load_byte,match_byte;
load_byte = cntx->latch | MASK_BYTE(cntx);
match_byte = MATCH_BYTE(cntx) | MASK_BYTE(cntx);
//LOG(("%02x %02x\n",load_byte,match_byte));
if(load_byte == match_byte)
MATCH_F_SET(cntx);
cntx->count--;
done = (cntx->count == 0xFFFF); //correct?
}
break;
case TM_SEARCH_TRANSFER:
@ -338,6 +351,7 @@ WRITE8_DEVICE_HANDLER( z80dma_w )
else if ((data & 0x83) == 0x80) // WR3
{
WR3(cntx) = data;
if (data & 0x08)
cntx->regs_follow[cntx->num_follow++] = GET_REGNUM(cntx, MASK_BYTE(cntx));
if (data & 0x10)
cntx->regs_follow[cntx->num_follow++] = GET_REGNUM(cntx, MATCH_BYTE(cntx));
@ -398,7 +412,7 @@ WRITE8_DEVICE_HANDLER( z80dma_w )
cntx->addressA = PORTA_ADDRESS(cntx);
cntx->addressB = PORTB_ADDRESS(cntx);
cntx->count = BLOCKLEN(cntx);
cntx->status &= ~0x30;
cntx->status |= 0x30;
LOG(("Load A: %x B: %x N: %x\n", cntx->addressA, cntx->addressB, cntx->count));
break;
case 0x83: /* Disable dma */
@ -420,7 +434,7 @@ WRITE8_DEVICE_HANDLER( z80dma_w )
cntx->count = 0;
cntx->dma_enabled = 1;
//"match not found" & "end of block" status flags zeroed here
cntx->status &= ~0x30;
cntx->status |= 0x30;
break;
case 0xc7: /* Reset Port A Timing */
LOG(("Reset Port A Timing\n"));
@ -444,9 +458,8 @@ WRITE8_DEVICE_HANDLER( z80dma_w )
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;
cntx->status |= 0x30;
break;
case 0xFB:
LOG(("Z80DMA undocumented command triggered 0x%02X!\n",data));