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fix(timer): increase accuracy of timer
continuous-integration/drone/push Build is passing Details

This commit is contained in:
Rekai Nyangadzayi Musuka 2021-08-20 00:17:28 -05:00
parent b87e31d3f4
commit d794a94b68
1 changed files with 38 additions and 14 deletions
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40
src/timer.rs
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@ -21,18 +21,29 @@ impl Timer {
use State::*;
use TimerSpeed::*;
if let TIMAOverflow(step) | AbortedTIMAOverflow(step) = self.state {
if step < 4 {
self.state = TIMAOverflow(step + 1);
return;
match self.state {
TIMAOverflow(_) | AbortedTIMAOverflow(_) => self.state = self.state.next(),
LoadTMA => {
self.counter = self.modulo;
self.interrupt = true;
self.state.next();
}
Normal => {}
}
if let TIMAOverflow(step) | AbortedTIMAOverflow(step) = self.state {
if step < 3 {
self.state = self.state.next();
} else {
if self.state == TIMAOverflow(step) {
self.counter = self.modulo;
self.interrupt = true;
}
self.state = Normal;
}
}
self.divider = self.divider.wrapping_add(1);
@ -67,14 +78,12 @@ impl Timer {
use State::*;
match self.state {
Normal => self.counter = byte,
Normal | AbortedTIMAOverflow(_) => self.counter = byte,
TIMAOverflow(step) => {
if step < 4 {
self.counter = byte;
self.state = AbortedTIMAOverflow(step);
}
}
AbortedTIMAOverflow(_) => self.counter = byte,
LoadTMA => {}
}
}
@ -173,4 +182,19 @@ enum State {
TIMAOverflow(u8),
AbortedTIMAOverflow(u8),
Normal,
LoadTMA,
}
impl State {
fn next(&self) -> Self {
use State::*;
match self {
Normal | LoadTMA => Normal,
TIMAOverflow(3) => LoadTMA,
AbortedTIMAOverflow(3) => Normal,
TIMAOverflow(step) => TIMAOverflow(step + 1),
AbortedTIMAOverflow(step) => AbortedTIMAOverflow(step + 1),
}
}
}