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My new reading is that only a write to the counter should affect the interrupt flag.

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This commit is contained in:
Thomas Harte 2020-09-17 21:31:29 -04:00
parent 18790a90ae
commit e807a462a1
1 changed files with 11 additions and 5 deletions
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16
Components/6522/Implementation/6522Implementation.hpp
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@ -74,13 +74,19 @@ template <typename T> void MOS6522<T>::write(int address, uint8_t value) {
case 0x6: case 0x4: // ('T1L-L' and 'T1C-L')
registers_.timer_latch[0] = (registers_.timer_latch[0]&0xff00) | value;
break;
case 0x5: case 0x7: // ('T1L-H' and 'T1C-H')
case 0x7: // Timer 1 latch, high ('T1L-H').
registers_.timer_latch[0] = (registers_.timer_latch[0]&0x00ff) | uint16_t(value << 8);
break;
case 0x5: // Timer 1 counter, high ('T1C-H').
// Fill latch.
registers_.timer_latch[0] = (registers_.timer_latch[0]&0x00ff) | uint16_t(value << 8);
// Restart timer.
registers_.next_timer[0] = registers_.timer_latch[0];
timer_is_running_[0] = true;
// Clear existing interrupt flag.
registers_.interrupt_flags &= ~InterruptFlag::Timer1;
if(address == 0x05) {
registers_.next_timer[0] = registers_.timer_latch[0];
timer_is_running_[0] = true;
}
reevaluate_interrupts();
break;