static TIMER_CALLBACK( dma8257_timerproc )
{
const device_config *device = (const device_config *)ptr;
dma8257_t *dma8257 = get_safe_token(device);
int i, channel = 0, rr;
int done;
rr = DMA_MODE_ROTPRIO(dma8257->mode) ? dma8257->rr : 0;
for (i = 0; i < DMA8257_NUM_CHANNELS; i++)
{
channel = (i + rr) % DMA8257_NUM_CHANNELS;
if ((dma8257->status & (1 << channel)) == 0)
if (dma8257->mode & dma8257->drq & (1 << channel))
break;
}
done = dma8257_do_operation(device, channel);
dma8257->rr = (channel + 1) & 0x03;
if (done)
{
dma8257->drq &= ~(0x01 << channel);
dma8257_update_status(device);
if (!(DMA_MODE_AUTOLOAD(dma8257->mode) && channel==2)) {
if (DMA_MODE_TCSTOP(dma8257->mode)) {
dma8257->mode &= ~(0x01 << channel);
}
}
}
}
void i8257_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
{
switch (id)
{
case TIMER_OPERATION:
{
int i, channel = 0, rr;
int done;
rr = DMA_MODE_ROTPRIO(m_mode) ? m_rr : 0;
for (i = 0; i < I8257_NUM_CHANNELS; i++)
{
channel = (i + rr) % I8257_NUM_CHANNELS;
if ((m_status & (1 << channel)) == 0)
{
if (m_mode & m_drq & (1 << channel))
{
break;
}
}
}
done = i8257_do_operation(channel);
m_rr = (channel + 1) & 0x03;
if (done)
{
m_drq &= ~(0x01 << channel);
i8257_update_status();
if (!(DMA_MODE_AUTOLOAD(m_mode) && channel==2))
{
if (DMA_MODE_TCSTOP(m_mode))
{
m_mode &= ~(0x01 << channel);
}
}
}
break;
}
case TIMER_MSBFLIP:
m_msb ^= 1;
break;
case TIMER_DRQ_SYNC:
{
int channel = param >> 1;
int state = param & 0x01;
/* normalize state */
if (state)
{
m_drq |= 0x01 << channel;
m_address[channel] = m_registers[channel * 2];
m_count[channel] = m_registers[channel * 2 + 1] & 0x3FFF;
m_rwmode[channel] = m_registers[channel * 2 + 1] >> 14;
/* clear channel TC */
m_status &= ~(0x01 << channel);
}
else
m_drq &= ~(0x01 << channel);
i8257_update_status();
break;
}
}
int i8257_device::i8257_do_operation(int channel)
{
int done;
UINT8 data;
UINT8 mode = m_rwmode[channel];
if (m_count[channel] == 0x0000)
{
m_status |= (0x01 << channel);
m_out_tc_func(ASSERT_LINE);
}
switch(mode) {
case 1:
if (!m_in_memr_func.isnull())
{
data = m_in_memr_func(m_address[channel]);
}
else
{
data = 0;
logerror("8257: No memory read function defined.\n");
}
if (!m_out_iow_func[channel].isnull())
{
m_out_iow_func[channel](m_address[channel], data);
}
else
{
logerror("8257: No channel write function for channel %d defined.\n",channel);
}
m_address[channel]++;
m_count[channel]--;
done = (m_count[channel] == 0xFFFF);
break;
case 2:
if (!m_in_ior_func[channel].isnull())
{
data = m_in_ior_func[channel](m_address[channel]);
}
else
{
data = 0;
logerror("8257: No channel read function for channel %d defined.\n",channel);
}
if (!m_out_memw_func.isnull())
{
m_out_memw_func(m_address[channel], data);
}
else
{
logerror("8257: No memory write function defined.\n");
}
m_address[channel]++;
m_count[channel]--;
done = (m_count[channel] == 0xFFFF);
break;
case 0: /* verify */
m_address[channel]++;
m_count[channel]--;
done = (m_count[channel] == 0xFFFF);
break;
default:
fatalerror("i8257_do_operation: invalid mode!\n");
break;
}
if (done)
{
if ((channel==2) && DMA_MODE_AUTOLOAD(m_mode))
{
/* in case of autoload at the end channel 3 info is */
/* copied to channel 2 info */
m_registers[4] = m_registers[6];
m_registers[5] = m_registers[7];
}
m_out_tc_func(CLEAR_LINE);
}
return done;
}
static int dma8257_do_operation(const device_config *device, int channel)
{
dma8257_t *dma8257 = get_safe_token(device);
int done;
UINT8 data;
UINT8 mode;
mode = dma8257->rwmode[channel];
if (dma8257->count[channel] == 0x0000)
{
dma8257->status |= (0x01 << channel);
if (dma8257->intf->out_tc[channel])
dma8257->intf->out_tc[channel](device, 0, ASSERT_LINE);
}
switch(mode) {
case 1:
if (dma8257->intf->memory_read!=NULL) {
data = dma8257->intf->memory_read(device, dma8257->address[channel]);
} else {
data = 0;
logerror("8257: No memory read function defined.\n");
}
if (dma8257->intf->channel_write[channel]!=NULL) {
dma8257->intf->channel_write[channel](device, 0, data);
} else {
logerror("8257: No channel write function for channel %d defined.\n",channel);
}
dma8257->address[channel]++;
dma8257->count[channel]--;
done = (dma8257->count[channel] == 0xFFFF);
break;
case 2:
if (dma8257->intf->channel_read[channel]!=NULL) {
data = dma8257->intf->channel_read[channel](device, 0);
} else {
data = 0;
logerror("8257: No channel read function for channel %d defined.\n",channel);
}
if (dma8257->intf->memory_write!=NULL) {
dma8257->intf->memory_write(device, dma8257->address[channel], data);
} else {
logerror("8257: No memory write function defined.\n");
}
dma8257->address[channel]++;
dma8257->count[channel]--;
done = (dma8257->count[channel] == 0xFFFF);
break;
case 0: /* verify */
dma8257->address[channel]++;
dma8257->count[channel]--;
done = (dma8257->count[channel] == 0xFFFF);
break;
default:
fatalerror("dma8257_do_operation: invalid mode!\n");
break;
}
if (done)
{
if ((channel==2) && DMA_MODE_AUTOLOAD(dma8257->mode)) {
/* in case of autoload at the end channel 3 info is */
/* copied to channel 2 info */
dma8257->registers[4] = dma8257->registers[6];
dma8257->registers[5] = dma8257->registers[7];
}
if (dma8257->intf->out_tc[channel])
dma8257->intf->out_tc[channel](device, 0, CLEAR_LINE);
}
return done;
}
