void dectalk_state::dectalk_clear_all_fifos( )
{
// clear fifos (TODO: memset would work better here...)
int i;
for (i=0; i<16; i++) m_outfifo[i] = 0;
for (i=0; i<32; i++) m_infifo[i] = 0;
m_outfifo_tail_ptr = m_outfifo_head_ptr = 0;
m_infifo_tail_ptr = m_infifo_head_ptr = 0;
dectalk_outfifo_check();
}
static void dectalk_clear_all_fifos( running_machine &machine )
{
dectalk_state *state = machine.driver_data<dectalk_state>();
// clear fifos (TODO: memset would work better here...)
int i;
for (i=0; i<16; i++) state->m_outfifo[i] = 0;
for (i=0; i<32; i++) state->m_infifo[i] = 0;
state->m_outfifo_tail_ptr = state->m_outfifo_head_ptr = 0;
state->m_infifo_tail_ptr = state->m_infifo_head_ptr = 0;
dectalk_outfifo_check(machine);
}
// read the output fifo and set the interrupt line active on the dsp
UINT16 dectalk_state::dectalk_outfifo_r ( )
{
UINT16 data = 0xFFFF;
data = m_outfifo[m_outfifo_tail_ptr];
// if fifo is empty (tail ptr == head ptr), do not increment the tail ptr, otherwise do.
//if (m_outfifo_tail_ptr != m_outfifo_head_ptr) m_outfifo_tail_ptr++; // technically correct but doesn't match sn74ls224 sheet
if (((m_outfifo_head_ptr-1)&0xF) != m_outfifo_tail_ptr) m_outfifo_tail_ptr++; // matches sn74ls224 sheet
m_outfifo_tail_ptr&=0xF;
dectalk_outfifo_check();
return ((data&0xfff0)^0x8000); // yes this is right, top bit is inverted and bottom 4 are ignored
//return data; // not right but want to get it working first
}
// read the output fifo and set the interrupt line active on the dsp
static UINT16 dectalk_outfifo_r ( running_machine &machine )
{
dectalk_state *state = machine.driver_data<dectalk_state>();
UINT16 data = 0xFFFF;
data = state->m_outfifo[state->m_outfifo_tail_ptr];
// if fifo is empty (tail ptr == head ptr), do not increment the tail ptr, otherwise do.
//if (state->m_outfifo_tail_ptr != state->m_outfifo_head_ptr) state->m_outfifo_tail_ptr++; // technically correct but doesn't match sn74ls224 sheet
if (((state->m_outfifo_head_ptr-1)&0xF) != state->m_outfifo_tail_ptr) state->m_outfifo_tail_ptr++; // matches sn74ls224 sheet
state->m_outfifo_tail_ptr&=0xF;
dectalk_outfifo_check(machine);
return ((data&0xfff0)^0x8000); // yes this is right, top bit is inverted and bottom 4 are ignored
//return data; // not right but want to get it working first
}
// read the output fifo and set the interrupt line active on the dsp
uint16_t dectalk_state::dectalk_outfifo_r ( )
{
uint16_t data = 0xFFFF;
#ifdef USE_LOOSE_TIMING_OUTPUT
// if outfifo count is less than two, boost the interleave to prevent running the fifo out
if (m_outfifo_count < 2)
machine().scheduler().boost_interleave(attotime::zero, attotime::from_usec(25));
#endif
#ifdef VERBOSE
if (m_outfifo_count == 0) logerror("output fifo is EMPTY! repeating previous sample!\n");
#endif
data = m_outfifo[m_outfifo_tail_ptr];
// if fifo is empty (tail ptr == head ptr), do not increment the tail ptr, otherwise do.
if (m_outfifo_count > 0)
{
m_outfifo_tail_ptr++;
m_outfifo_count--;
}
m_outfifo_tail_ptr&=0xF;
dectalk_outfifo_check();
return ((data&0xfff0)^0x8000); // yes this is right, top bit is inverted and bottom 4 are ignored
//return data; // not right but want to get it working first
}