stm32f042_hal/
delay.rs

1//! Delays
2
3use cast::u32;
4use cortex_m::peripheral::syst::SystClkSource;
5use cortex_m::peripheral::SYST;
6
7use hal::blocking::delay::{DelayMs, DelayUs};
8use rcc::Clocks;
9
10/// System timer (SysTick) as a delay provider
11pub struct Delay {
12    clocks: Clocks,
13    syst: SYST,
14}
15
16impl Delay {
17    /// Configures the system timer (SysTick) as a delay provider
18    pub fn new(mut syst: SYST, clocks: Clocks) -> Self {
19        syst.set_clock_source(SystClkSource::Core);
20
21        Delay { syst, clocks }
22    }
23
24    /// Releases the system timer (SysTick) resource
25    pub fn free(self) -> SYST {
26        self.syst
27    }
28}
29
30impl DelayMs<u32> for Delay {
31    fn delay_ms(&mut self, ms: u32) {
32        self.delay_us(ms * 1_000);
33    }
34}
35
36impl DelayMs<u16> for Delay {
37    fn delay_ms(&mut self, ms: u16) {
38        self.delay_ms(u32(ms));
39    }
40}
41
42impl DelayMs<u8> for Delay {
43    fn delay_ms(&mut self, ms: u8) {
44        self.delay_ms(u32(ms));
45    }
46}
47
48impl DelayUs<u32> for Delay {
49    fn delay_us(&mut self, us: u32) {
50        let rvr = us * (self.clocks.sysclk().0 / 1_000_000);
51
52        assert!(rvr < (1 << 24));
53
54        self.syst.set_reload(rvr);
55        self.syst.clear_current();
56        self.syst.enable_counter();
57
58        while !self.syst.has_wrapped() {}
59
60        self.syst.disable_counter();
61    }
62}
63
64impl DelayUs<u16> for Delay {
65    fn delay_us(&mut self, us: u16) {
66        self.delay_us(u32(us))
67    }
68}
69
70impl DelayUs<u8> for Delay {
71    fn delay_us(&mut self, us: u8) {
72        self.delay_us(u32(us))
73    }
74}
stm32f042_hal/delay.rs

stm32f042_hal/
delay.rs
