stm8s003MCU_PWM_pin function configuration

I am currently developing an LED light product using the stm8s003 MCU. I am using the PWM output function of TIM2, using TIM2_CHANNEL3, and the PA3 pin is multiplexed as TIM2_CH3.

1. How to reuse the PA3 pin as TIM2_CH3

The pin multiplexing function of stm8MCU is not like the NXP MCU or 51MCU I have used before. The NXP MCU pins used before have dedicated pin function configuration registers, and the pins can be configured to different functions through the configuration registers. The pins of stm8MCU have a main function (after reset), which is the main function of the pin after reset. In addition, the pin has a default alternet function, for example: the default alternet function of PA3 is TIM2_CH3. If you want to use TIM2_CH3, you only need to configure the TIM2_CH3 function when TIMER2 is initialized and enable TIMER2 to use the TIM2_CH3 function.

In the pin description of stm8MCU, you can also see that the pin has an alternet function after remap [option bit]. The function in [ ] refers to the pin function that can be realized by configuring AFR through STVP software.

2. Output status of PWM function pin after stm8 timer stops

After the stm8s timer function stops, the PWM function output of the channel pin corresponding to the timer is in an uncertain state. So if you want to keep the PWM function pin in a certain state after turning off the timer, such as turning off the PWM function and outputting a low level. This requires configuring the CCMR1 register of the timer. As shown below, using the library function, after TIMER2 is turned off, keep the pin output low level:

TIM2_Cmd(DISABLE);  

/* Pull the level to low after stopping PWM */  

TIM2_ForcedOC1Config(TIM2_FORCEDACTION_INACTIVE);