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via6522: fixed 50/50 duty cycle for T2 and O2 driven CB1 shift IN & OUT on CB2

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This commit is contained in:
Joakim Larsson Edstrom 2017-01-30 23:55:50 +01:00
parent 5d038a8353
commit e5b54e8650
1 changed files with 23 additions and 19 deletions
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42
src/devices/machine/6522via.cpp
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@ -355,7 +355,7 @@ void via6522_device::shift_out()
if (!SO_T2_RATE(m_acr))
{
m_shift_counter = (m_shift_counter + 1) % 8;
m_shift_counter = (m_shift_counter - 1) & 7;
if (m_shift_counter == 0)
{
@ -370,7 +370,7 @@ void via6522_device::shift_in()
m_sr = (m_sr << 1) | (m_in_cb2 & 1);
LOGSHIFT("%02x\n", m_sr);
m_shift_counter = (m_shift_counter + 1) % 8;
m_shift_counter = (m_shift_counter - 1) & 7;
if (m_shift_counter == 0)
{
@ -385,31 +385,33 @@ void via6522_device::device_timer(emu_timer &timer, device_timer_id id, int para
{
case TIMER_SHIFT:
LOGSHIFT("SHIFT timer event\n");
m_out_cb1 = 0;
m_out_cb1 ^= 1;
m_cb1_handler(m_out_cb1);
if (SO_T2_RATE(m_acr) || SO_T2_CONTROL(m_acr) || SO_O2_CONTROL(m_acr))
if (m_out_cb1 & 1) // raising flank
{
shift_out();
if (SI_T2_CONTROL(m_acr) || SI_O2_CONTROL(m_acr))
{
shift_in();
}
}
m_out_cb1 = 1;
m_cb1_handler(m_out_cb1);
if (SI_T2_CONTROL(m_acr) || SI_O2_CONTROL(m_acr))
else // falling flank
{
shift_in();
if (SO_T2_RATE(m_acr) || SO_T2_CONTROL(m_acr) || SO_O2_CONTROL(m_acr))
{
shift_out();
}
}
if (SO_T2_RATE(m_acr) || m_shift_counter)
{
if (SI_O2_CONTROL(m_acr) || SO_O2_CONTROL(m_acr))
{
m_shift_timer->adjust(clocks_to_attotime(2));
m_shift_timer->adjust(clocks_to_attotime(1));
}
else
{
m_shift_timer->adjust(clocks_to_attotime((m_t2ll + 2)*2));
m_shift_timer->adjust(clocks_to_attotime(m_t2ll + 2));
}
}
break;
@ -624,15 +626,16 @@ READ8_MEMBER( via6522_device::read )
case VIA_SR:
LOGSHIFT("Read SR: %02x\n", m_sr);
val = m_sr;
m_shift_counter=0;
m_out_cb1 = 1;
m_shift_counter = 8;
clear_int(INT_SR);
if (SI_O2_CONTROL(m_acr))
{
m_shift_timer->adjust(clocks_to_attotime(2));
m_shift_timer->adjust(clocks_to_attotime(1));
}
if (SI_T2_CONTROL(m_acr))
{
m_shift_timer->adjust(clocks_to_attotime((m_t2ll + 2)*2));
m_shift_timer->adjust(clocks_to_attotime(m_t2ll + 2));
}
break;
@ -787,15 +790,16 @@ WRITE8_MEMBER( via6522_device::write )
case VIA_SR:
m_sr = data;
LOGSHIFT("Write SR: %02x\n", m_sr);
m_shift_counter=0;
m_out_cb1 = 1;
m_shift_counter = 8;
clear_int(INT_SR);
if (SO_O2_CONTROL(m_acr))
{
m_shift_timer->adjust(clocks_to_attotime(2));
m_shift_timer->adjust(clocks_to_attotime(1));
}
if (SO_T2_RATE(m_acr) || SO_T2_CONTROL(m_acr))
{
m_shift_timer->adjust(clocks_to_attotime((m_t2ll + 2)*2));
m_shift_timer->adjust(clocks_to_attotime(m_t2ll + 2));
}
break;