/*
should be called after any change to int_state or enabled_ints.
*/
void tms9901_device::field_interrupts()
{
int current_ints;
// m_int_state: inverted state of lines INT1*-INT15*. Bits are set by set_single_int only.
current_ints = m_int_state;
if (m_clock_register != 0)
{
// if timer is enabled, INT3 pin is overridden by timer
if (m_timer_int_pending)
{
LOGMASKED(LOG_INT, "INT3 (timer) asserted\n");
current_ints |= INT3;
}
else
{
LOGMASKED(LOG_INT, "INT3 (timer) cleared\n");
current_ints &= ~INT3;
}
}
// enabled_ints: enabled interrupts
// Remove all settings from pins that are set as outputs (INT7*-INT15* share the same pins as P15-P7)
current_ints &= m_enabled_ints & (~m_pio_direction_mirror);
// Check whether we have a new state. For systems that use level-triggered
// interrupts it should not do any harm if the line is re-asserted
// but we may as well avoid this.
if (current_ints == m_old_int_state)
return;
m_old_int_state = current_ints;
if (current_ints != 0)
{
// find which interrupt tripped us:
// the number of the first (i.e. least significant) non-zero bit among
// the 16 first bits
// we simply look for the first bit set to 1 in current_ints...
int level = 0;
while ((current_ints & 1)==0)
{
current_ints >>= 1; /* try next bit */
level++;
}
LOGMASKED(LOG_INT, "Triggering interrupt, level %d\n", level);
m_int_pending = true;
if (!m_interrupt.isnull())
m_interrupt(level, 1, 0xff); // the offset carries the IC0-3 level
}
/*
should be called after any change to int_state or enabled_ints.
*/
void tms9901_device::field_interrupts(void)
{
int current_ints;
/* int_state: state of lines int1-int15 */
current_ints = m_int_state;
if (m_clock_register != 0)
{ /* if timer is enabled, INT3 pin is overriden by timer */
if (m_timer_int_pending)
{
if (VERBOSE>8) LOG("tms9901: timer fires\n");
current_ints |= TMS9901_INT3;
}
else
{
if (VERBOSE>8) LOG("tms9901: timer clear\n");
current_ints &= ~TMS9901_INT3;
}
}
/* enabled_ints: enabled interrupts */
/* mask out all int pins currently set as output */
current_ints &= m_enabled_ints & (~m_pio_direction_mirror);
// Check whether we have a new state. For systems that use level-triggered
// interrupts it should not do any harm if the line is re-asserted
// but we may as well avoid this.
if (current_ints == m_old_int_state)
return;
m_old_int_state = current_ints;
if (current_ints)
{
// find which interrupt tripped us:
// the number of the first (i.e. least significant) non-zero bit among
// the 16 first bits
// we simply look for the first bit set to 1 in current_ints... */
int level = 0;
while ((current_ints & 1)==0)
{
current_ints >>= 1; /* try next bit */
level++;
}
m_int_pending = true;
if (!m_interrupt.isnull())
m_interrupt(level, 1); // the offset carries the IC0-3 level
}
else
{
void BaseIndex::Interrupt()
{
m_interrupt();
}
