Please help explain this procedure

shijizai

Please help explain this procedure [Copy link]

  temp = ((uint32_t)(GPIO_AF) << ((uint32_t)((uint32_t)GPIO_PinSource & (uint32_t)0x07) * 4)) ; GPIOx->AFR[GPIO_PinSource >> 0x03] &= ~((uint32_t)0xF < < ((uint32_t)((uint32_t)GPIO_PinSource & (uint32_t)0x07) * 4)) ; temp_2 = GPIOx->AFR[GPIO_PinSource >> 0x03] | temp; GPIOx->AFR[GPIO_PinSource >> 0x03] = temp_2;

star_66666

  temp = ((uint32_t)(GPIO_AF) << ((uint32_t)((uint32_t)GPIO_PinSource & (uint32_t)0x07) * 4)) ; Read the AF register value GPIOx->AFR[GPIO_PinSource >> 0x03] &= ~( (uint32_t)0xF << ((uint32_t)((uint32_t)GPIO_PinSource & (uint32_t)0x07) * 4)) ;Clear some bits temp_2 = GPIOx->AFR[GPIO_PinSource >> 0x03] | temp; GPIOx->AFR[GPIO_PinSource >> 0x03] = temp_2; The last two are very simple to assign values to the AFR register. Are you a beginner?

star_66666

It’s more comfortable to use register configuration. I feel dizzy just looking at these official ones. I don’t like them.

shijizai

[ color=#999999]star_66666 published on 2018-7-20 10:11 It is more comfortable to use register configuration. I feel dizzy looking at these official ones. I don’t like it.

Register: congratulate: I also have a problem with the register, #define DS18B20_IO_IN1() {GPIOA->MODER&= 0<<30;GPIOA->MODER&= 0<<31;GPIOA->MODER|=0<<15* 2;} #define DS18B20_IO_OUT1() {GPIOA->MODER&= 0<<30;GPIOA->MODER&= 0<<31;GPIOA->MODER|=1<<15*2;} This is the operation of stm32F405, I I want to clear PA15 first and then assign a value. (Unfortunately, PA14 and PA13 next to PA15 are my download pins.) Master, see if there is something wrong in these two sentences. I can't burn the program into the program board when I click on it. After downloading this program, the board can no longer burn programs: Cry:

shijizai

star_66666 Published on 2018-7-20 10:10 temp = ((uint32_t)(GPIO_AF) AFR[GPIO_PinSource >> 0x03] &= ~((uint32_t)0xF AFR[GPIO_PinSource >> ...

Then why 0x07*4?

star_66666

It seems that brother is really a beginner among beginners. It’s a very simple question. Come on young man, the road is still long. Take your time.,,

shijizai

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