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Add timer X counting.

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Still no interrupts.
This commit is contained in:
Thomas Harte 2021-02-15 16:29:25 -05:00
parent f5dcff2f29
commit f8f0ff0fae
1 changed files with 29 additions and 8 deletions
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37
InstructionSets/M50740/Executor.cpp
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@ -775,26 +775,47 @@ template <Operation operation> void Executor::perform(uint8_t *operand [[maybe_u
}
inline void Executor::subtract_duration(int duration) {
// Pass along.
CachingExecutor::subtract_duration(duration);
// Update count for potential port accesses.
cycles_since_port_handler_ += Cycles(duration);
// Update timer 1 and 2 prescaler.
constexpr int t12_divider = 4; // TODO: should be 4, I think.
constexpr int t12_multiplier = 1;
constexpr int t12_divider = 4; // A divide by 4 has already been applied before counting instruction lengths; therefore
// this additional divide by 4 produces the correct net divide by 16.
timer_divider_ += duration * t12_multiplier;
timer_divider_ += duration;
const int t12_ticks = update_timer(prescalers_[0], timer_divider_ / t12_divider);
timer_divider_ &= (t12_divider-1);
// Update timers 1 and 2. TODO: interrupts (elsewhere).
// Update timers 1 and 2. TODO: interrupts (elsewhere?).
if(update_timer(timers_[0], t12_ticks)) interrupt_control_ |= 0x20;
if(update_timer(timers_[1], t12_ticks)) interrupt_control_ |= 0x08;
// TODO: timer X.
// update_timer(timers_[2], update_timer(prescalers_[1], duration));
// If timer X is disabled, stop.
if(timer_control_&0x20) {
return;
}
// Pass along.
CachingExecutor::subtract_duration(duration);
// Update timer X prescaler.
switch(timer_control_ & 0x0c) {
default: {
const int tx_ticks = update_timer(prescalers_[1], duration * 4); // Update at 3.58Mhz.
if(update_timer(timers_[2], tx_ticks))
timer_control_ |= 0x80; // TODO: interrupt result of this.
} break;
case 0x04:
LOG("TODO: Timer X; Pulse output mode");
break;
case 0x08:
LOG("TODO: Timer X; Event counter mode");
break;
case 0x0c:
LOG("TODO: Timer X; Pulse width measurement mode");
break;
}
// update_timer(timers_[2], update_timer(prescalers_[1], duration));
}
inline int Executor::update_timer(Timer &timer, int count) {