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Corrects in-service test; adds pending clearing upon enabled clearing.

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This commit is contained in:
Thomas Harte 2019-10-28 22:51:00 -04:00
parent 553f3b6d8b
commit fd02b6fc18
1 changed files with 7 additions and 3 deletions
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10
Components/68901/MFP68901.cpp
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@ -95,10 +95,14 @@ void MFP68901::write(int address, uint8_t value) {
case 0x03:
LOG("Write: interrupt enable A " << PADHEX(2) << int(value));
interrupt_enable_ = (interrupt_enable_ & 0x00ff) | (value << 8);
interrupt_pending_ = (interrupt_enable_ & 0x00ff) | (value << 8);
update_interrupts();
break;
case 0x04:
LOG("Write: interrupt enable B " << PADHEX(2) << int(value));
interrupt_enable_ = (interrupt_enable_ & 0xff00) | value;
interrupt_pending_ = (interrupt_enable_ & 0xff00) | value;
update_interrupts();
break;
case 0x05:
LOG("Write: interrupt pending A " << PADHEX(2) << int(value));
@ -312,10 +316,10 @@ void MFP68901::update_interrupts() {
interrupt_line_ = false;
} else {
if(interrupt_vector_ & 0x8) {
// Software interrupt mode: permit only if no higher interrupts
// are currently in service.
// Software interrupt mode: permit only if neither this interrupt
// nor a higher interrupt is currently in service.
const int highest_bit = 1 << (fls(firing_interrupts) - 1);
interrupt_line_ = !(interrupt_in_service_ & ~(highest_bit + highest_bit - 1));
interrupt_line_ = !(interrupt_in_service_ & ~(highest_bit - 1));
} else {
// Auto-interrupt mode; just signal.
interrupt_line_ = true;