embassy/embassy-stm32/src/crc/v1.rs
2022-02-10 16:06:42 +01:00

57 lines
1.6 KiB
Rust

use core::marker::PhantomData;
use crate::pac::CRC as PAC_CRC;
use crate::peripherals::CRC;
use crate::rcc::sealed::RccPeripheral;
use embassy::util::Unborrow;
use embassy_hal_common::unborrow;
pub struct Crc<'d> {
_peripheral: CRC,
_phantom: PhantomData<&'d mut CRC>,
}
impl<'d> Crc<'d> {
/// Instantiates the CRC32 peripheral and initializes it to default values.
pub fn new(peripheral: impl Unborrow<Target = CRC> + 'd) -> Self {
// Note: enable and reset come from RccPeripheral.
// enable CRC clock in RCC.
CRC::enable();
// Reset CRC to default values.
CRC::reset();
// Unborrow the peripheral
unborrow!(peripheral);
let mut instance = Self {
_peripheral: peripheral,
_phantom: PhantomData,
};
instance.reset();
instance
}
/// Resets the CRC unit to default value (0xFFFF_FFFF)
pub fn reset(&mut self) {
unsafe { PAC_CRC.cr().write(|w| w.set_reset(true)) };
}
/// Feeds a word to the peripheral and returns the current CRC value
pub fn feed_word(&mut self, word: u32) -> u32 {
// write a single byte to the device, and return the result
unsafe {
PAC_CRC.dr().write_value(word);
}
self.read()
}
/// Feed a slice of words to the peripheral and return the result.
pub fn feed_words(&mut self, words: &[u32]) -> u32 {
for word in words {
unsafe { PAC_CRC.dr().write_value(*word) }
}
self.read()
}
pub fn read(&self) -> u32 {
unsafe { PAC_CRC.dr().read() }
}
}