Stm32 Register Version Learning note PWM

STM32 can generate PWM output in addition to TIM6 and TIM7. The advanced timer TIM1 and TIM8 can simultaneously generate 7-way PWM, and the universal timer can generate 4 PWM outputs.

1.TIM1 CH1 Output PWM configuration steps

① turn on TIM1 clock, configure PA8 for multiplexed output

APB2 Peripheral Clock Enable register (RCC_APB2ENR)

APB1 Peripheral Reset Register (RCC_APB1RSTR)

Set 1 to open. Clear 0 closed.

eg:rcc->apb2enr|=1<<11; Enable TIM1 clock

Configuring I/O ports: See Stm32 Register Edition Learning Note the configuration of the Gpio port.

eg:gpioa->crh&=0xfffffff0; PA8 before clearing the settings

gpioa->crh|=0x0000000b; PA8 multiplexing function output

② set arr and PSC for TIM1

Automatic reload Register (Timx_arr)

TIM1 and TIM8 Prescaler (TIMX_PSC)

③ Setting the PWM mode and channel direction of the TIM1_CH1

TIM1 and TIM8 Capture/Compare Mode Register 1 (TIMX_CCMR1)

　　

eg:tim1->ccmr1|= 7<<4; CH1 PWM2 Mode

tim1->ccmr1|= 1<<3; CH1 Pre-load enable

CH1 is output, cc1s[1:0] defaults to 00.

④ enables the TIM1 CH1 output, enabling the TIM1 to be

Set Tim1_ccer to turn on the output of Channel 1 for TIM1. Set the TIM1_CR1 to turn on the TIM1 clock.

TIM1 and TIM8 capture/Compare Enable registers (Timx_ccer)

eg:tim1->ccer|= 1<<3; OC1 output Enable

TIM1 and TIM8 Control register 1 (TIMX_CR1)

Arpe: Automatic reload preload allows bit 0:timx_arr register without buffering; 1:timx_arr registers are loaded into buffers.

CEN: Enable counter bit 0 0: Disable counter; 1: Enable counter.

eg:tim1->cr1=0x0080; Arpe Enable

tim1->cr1|=0x01; Enable Timer 1

⑤ set Moe output to enable PWM output

The normal timer can output PWM after completing the above settings, but the advanced timer must be able to brake and dead-zone registers.

TIM1 and TIM8 brakes and dead-zone registers (TIMX_BDTR)

eg:tim1->bdtr|=1<<15; Moe Main output Enable

⑥ modify TIM1_CCR1 to control duty ratio

Eg: #define Pwm_val TIM1->CCR1 (can be set directly)

2. Advanced Timer TIM1 Output PWM application

1 //timer.c 2 //tim1_ch1 PWM Output Initialization3 //arr: Auto Reload values4 //PSC: Clock Prescaler frequency5 voidTim1_pwm_init (U16 arr,u16 PSC)6 {                              7     //This section needs to manually modify the IO port settings8rcc->apb2enr|=1<< One;//TIM1 Clock Enable9gpioa->crh&=0xfffffff0;//PA8 before clearing the settingsTengpioa->crh|=0x0000000b;//multiplexing function Output One      Atim1->arr=arr;//Set counter Auto reload value -tim1->psc=psc;//prescaler Settings -    thetim1->ccmr1|=7<<4;//CH1 PWM2 Mode -tim1->ccmr1|=1<<3;//CH1 Pre-load enable -tim1->ccer|=1<<0;//OC1 output Enable -tim1->bdtr|=1<< the;//MOE main output Enable +  -tim1->cr1=0x0080;//Arpe Enable +tim1->cr1|=0x01;//Enable timer 1 A}

1 //Timer.h2 #ifndef __timer_h3 #define__timer_h4#include"Sys.h" 5 //change the duty ratio by changing the value of the TIM1->CCR1 to control the brightness of the LED06 #defineLed0_pwm_val TIM1->CCR17 8 voidTim1_pwm_init (U16 arr,u16 PSC);9 #endif

3. Normal timer TIM2 Output 2 way PWM application

1 //tim2_ch3~4 PWM Output Initialization2 //arr: Auto Reload values3 //PSC: Clock Prescaler frequency4 voidTim2_pwm_init (U16 arr,u16 PSC)5 {                              6     //This section needs to manually modify the IO port settings7rcc->apb1enr|=1<<0;//TIM2 Clock Enable8gpioa->crl&=0xffff00ff;//pa2-3 before clearing the settings9gpioa->crl|=0x0000bb00;//multiplexing function OutputTen      Onetim2->arr=arr;//Set counter Auto reload value Atim2->psc=psc;//prescaler Settings -    -      thetim2->ccmr2|=7<<4;//CH3 PWM2 mode (output) -tim2->ccmr2|=1<<3;//CH3 Pre-load enable -tim2->ccer|=1<<8;//OC3 output Enable -      +tim2->ccmr2|=7<< A;//CH4 PWM2 mode (output) -tim2->ccmr2|=1<< One;//CH4 Pre-load enable +tim2->ccer|=1<< A;//OC4 output Enable A  attim2->cr1=0x0080;//Arpe Enable -tim2->cr1|=0x01;//Enable timer 2 - }   -  -  - //set duty ratio duty<899 in //set how much is the low - voidPwm_duty1 (U16 duty) to { +      -tim2->ccr3=duty; the } *  $ voidPwm_duty2 (U16 duty)Panax Notoginseng {                       -tim2->ccr4=duty; the}

Remember to add an output function before the main function!

Eg:tim2_pwm_init (899,0);//Do not divide. PWM frequency =72000/(899+1) =80khz

Stm32 Register Version Learning note PWM