embassy/examples/stm32f2/src/bin/pll.rs
2023-11-13 01:59:33 +01:00

56 lines
1.7 KiB
Rust

#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]
use core::convert::TryFrom;
use defmt::*;
use embassy_executor::Spawner;
use embassy_stm32::time::Hertz;
use embassy_stm32::Config;
use embassy_time::Timer;
use {defmt_rtt as _, panic_probe as _};
#[embassy_executor::main]
async fn main(_spawner: Spawner) {
// Example config for maximum performance on a NUCLEO-F207ZG board
let mut config = Config::default();
{
use embassy_stm32::rcc::*;
// By default, HSE on the board comes from a 8 MHz clock signal (not a crystal)
config.rcc.hse = Some(Hse {
freq: Hertz(8_000_000),
mode: HseMode::Bypass,
});
// PLL uses HSE as the clock source
config.rcc.pll_src = PllSource::HSE;
config.rcc.pll = Some(Pll {
// 8 MHz clock source / 8 = 1 MHz PLL input
prediv: unwrap!(PllPreDiv::try_from(8)),
// 1 MHz PLL input * 240 = 240 MHz PLL VCO
mul: unwrap!(PllMul::try_from(240)),
// 240 MHz PLL VCO / 2 = 120 MHz main PLL output
divp: Some(PllPDiv::DIV2),
// 240 MHz PLL VCO / 5 = 48 MHz PLL48 output
divq: Some(PllQDiv::DIV5),
divr: None,
});
// System clock comes from PLL (= the 120 MHz main PLL output)
config.rcc.sys = Sysclk::PLL1_P;
// 120 MHz / 4 = 30 MHz APB1 frequency
config.rcc.apb1_pre = APBPrescaler::DIV4;
// 120 MHz / 2 = 60 MHz APB2 frequency
config.rcc.apb2_pre = APBPrescaler::DIV2;
}
let _p = embassy_stm32::init(config);
loop {
Timer::after_millis(1000).await;
info!("1s elapsed");
}
}