documentation-example.c

TIMx->PSC = 47;
TIMx->ARR = 8;
TIMx->CCR1 = 4;
TIMx->CCMR1 |= TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1PE;
TIMx->CCER |= TIM_CCER_CC1E;
TIMx->BDTR |= TIM_BDTR_MOE;
TIMx->CR1 |= TIM_CR1_CEN;
TIMx->EGR |= TIM_EGR_UG;

fan-tim1.rs

// RCC initialisation
let mut rcc = device
    .RCC
    .configure()
    .usbsrc(USBClockSource::HSI48)
    .hsi48()
    .enable_crs(device.CRS)
    .sysclk(48.mhz())
    .pclk(24.mhz())
    .freeze(&mut device.FLASH);

// GPIO initialisation
let gpioa = device.GPIOA.split(&mut rcc);
let pwm3 = interrupt::free(|cs| {
        gpioa.pa8.into_push_pull_output(cs).into_alternate_af2(cs)
});

// Setup PWM timers
let tim1 = device.TIM1;

// Configure pre-scaler for 48 MHz / (47 + 1) = 1 MHz
tim1.psc.write(|w| w.psc().bits(47));

// Configure auto-reload register for (39 + 1) / 1 MHz = 25 kHz
tim1.arr.write(|w| w.arr().bits(39));

// Set half duty cycle (half of ARR)
tim1.ccr1.write(|w| w.ccr().bits(20));

tim1.ccmr1_output()
    .write(|w| w.oc1pe().set_bit().oc1m().pwm_mode1());
tim1.ccer.write(|w| w.cc1e().set_bit());
tim1.bdtr.write(|w| w.moe().set_bit());
tim1.cr1.write(|w| w.cen().set_bit());
tim1.egr.write(|w| w.ug().set_bit());