static void set_pc_bit(const device_config *device, int bit, int state)
{
i8255a_t *i8255a = get_safe_token(device);
/* set output latch bit */
i8255a->output[PORT_C] &= ~(1 << bit);
i8255a->output[PORT_C] |= state << bit;
switch (group_mode(i8255a, GROUP_A))
{
case MODE_1:
if (port_mode(i8255a, PORT_A) == MODE_OUTPUT)
{
switch (bit)
{
case 3: set_intr(i8255a, PORT_A, state); break;
case 6: set_inte(i8255a, PORT_A, state); break;
case 7: set_obf(i8255a, PORT_A, state); break;
}
}
else
{
switch (bit)
{
case 3: set_intr(i8255a, PORT_A, state); break;
case 4: set_inte(i8255a, PORT_A, state); break;
case 5: set_ibf(i8255a, PORT_A, state); break;
}
}
break;
case MODE_2:
switch (bit)
{
case 3: set_intr(i8255a, PORT_A, state); break;
case 4: set_inte2(i8255a, state); break;
case 5: set_ibf(i8255a, PORT_A, state); break;
case 6: set_inte1(i8255a, state); break;
case 7: set_obf(i8255a, PORT_A, state); break;
}
break;
}
if (group_mode(i8255a, GROUP_B) == MODE_1)
{
switch (bit)
{
case 0: set_intr(i8255a, PORT_B, state); break;
case 1:
if (port_mode(i8255a, PORT_B) == MODE_OUTPUT)
set_obf(i8255a, PORT_B, state);
else
set_ibf(i8255a, PORT_B, state);
break;
case 2: set_inte(i8255a, PORT_B, state); break;
}
}
output_pc(i8255a);
}
uint8_t i8255_device::read_mode1(int port)
{
uint8_t data;
if (port_mode(port) == MODE_OUTPUT)
{
// read data from output latch
data = m_output[port];
}
else
{
// read data from input latch
data = m_input[port];
// clear input buffer full flag
set_ibf(port, 0);
// clear interrupt
set_intr(port, 0);
// clear input latch
m_input[port] = 0;
}
return data;
}
static UINT8 read_mode2(i8255a_t *i8255a)
{
UINT8 data = 0;
/* read data from input latch */
data = i8255a->input[PORT_A];
/* clear input buffer full flag */
set_ibf(i8255a, PORT_A, 0);
/* clear interrupt */
set_intr(i8255a, PORT_A, 0);
return data;
}
uint8_t i8255_device::read_mode2()
{
uint8_t data;
// read data from input latch
data = m_input[PORT_A];
// clear input buffer full flag
set_ibf(PORT_A, 0);
// clear interrupt
set_intr(PORT_A, 0);
// clear input latch
m_input[PORT_A] = 0;
return data;
}
static UINT8 read_mode1(i8255a_t *i8255a, int port)
{
UINT8 data = 0;
if (port_mode(i8255a, port) == MODE_OUTPUT)
{
/* read data from output latch */
data = i8255a->output[port];
}
else
{
/* read data from input latch */
data = i8255a->input[port];
/* clear input buffer full flag */
set_ibf(i8255a, port, 0);
/* clear interrupt */
set_intr(i8255a, port, 0);
}
return data;
}
void i8255_device::set_pc_bit(int bit, int state)
{
// set output latch bit
m_output[PORT_C] &= ~(1 << bit);
m_output[PORT_C] |= state << bit;
switch (group_mode(GROUP_A))
{
case MODE_1:
if (port_mode(PORT_A) == MODE_OUTPUT)
{
switch (bit)
{
case 3: set_intr(PORT_A, state); break;
case 6: set_inte(PORT_A, state); break;
case 7: set_obf(PORT_A, state); break;
default: break;
}
}
else
{
switch (bit)
{
case 3: set_intr(PORT_A, state); break;
case 4: set_inte(PORT_A, state); break;
case 5: set_ibf(PORT_A, state); break;
default: break;
}
}
break;
case MODE_2:
switch (bit)
{
case 3: set_intr(PORT_A, state); break;
case 4: set_inte2(state); break;
case 5: set_ibf(PORT_A, state); break;
case 6: set_inte1(state); break;
case 7: set_obf(PORT_A, state); break;
default: break;
}
break;
}
if (group_mode(GROUP_B) == MODE_1)
{
switch (bit)
{
case 0: set_intr(PORT_B, state); break;
case 1:
if (port_mode(PORT_B) == MODE_OUTPUT)
set_obf(PORT_B, state);
else
set_ibf(PORT_B, state);
break;
case 2: set_inte(PORT_B, state); break;
default: break;
}
}
output_pc();
}