STM32 assignment question

csz9981

STM32 assignment question [Copy link]

Please advise on STM32 value assignment #include "stm32f10x.h" int main(void) { unsigned int a0,b0,c0,a1,b1,c1,a2,b2,c2; //initial value a0=*(unsigned int *)0x40010000;//CRL b0=*(unsigned int *)0x40021018;//RCC c0=*(unsigned int *)0x40010c0c;//ODR //value to be assigned a1=(1<<(4*0)); b1= (1<<3); c1=~(1<<0); //input value *(unsigned int *)0x40010000 |= (1<<(4*0)); //CRL port configuration L *(unsigned int *)0x40021018 |= (1<<3); //RCC clock *(unsigned int *)0x40010c0c &= ~(1<<0);//ODR data //Calculated value a2=*(unsigned int *)0x40010000;//CRL b2=*(unsigned int *)0x40021018;//RCC c2=*(unsigned int *)0x40010c0c;//ODR } void SystemInit(void) { //No error} After debugging, it is found that a0b0c0 is different from the initial value in the reference manual, and a1b1c1 is the same as the planned value. a2b2c2, and finally all are 000. What is the reason?

cruelfox

Why not use the existing register definitions in the header file? If you really want to write your own, the pointer must be modified with the volatile keyword.

lcofjp

I don't know if you are using software simulation or connecting to a development board for simulation. The software prompts that you do not have read and write permissions to the corresponding memory, so you cannot read or write the contents.

chenbingjy

Are some bits of the register not writable?

ddllxxrr

void SystemInit(void) { //No error} This function is not allowed to be like this. Let's take a test. It seems to be responsible for allocating sectors.

csz9981

ddllxxrr posted on 2019-3-30 19:50 void SystemInit(void) { //No error} This function cannot be done like this. Let's take a test. It seems to be responsible for allocating...

It's possible.