• State Accepted Answer
  • Locked Locked
  • Replies 3 replies
  • Subscribers 119 subscribers
  • Views 11868 views
  • Users 0 members are here
Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Procedure for Init GPIO

Nguyen Nhat Minh

Hi guy,

I'm using ARM STM32F103RC, Cortex M3.

when I compiler the code with this order:

  //GPIO structure used to initialize port

  GPIO_InitTypeDef GPIO_InitStructure;

   

    //Enable clock on APB2 pripheral bus where button and LEDs are connected

  RCC_APB2PeriphClockCmd(LEDPORTCLK | BUTTONPORTCLK,  ENABLE);

 

is okay,

But I want to enable clock first,

the compiler give the error

main.c(28): error:  #268: declaration may not appear after executable statement in block

    GPIO_InitTypeDef  GPIO_InitStructure;

would you like to explain to me why this happened?

Minh

Parents
  • 0

    Hi Minh,

    Thanks for your question.

    I think you will find that the first statement "GPIO_InitTypeDef GPIO_InitStructure;" is a declaration, not an executable statement. I assume what you are doing is moving that statement to below the next line, in the hope that this will enable the clock before enabling the GPIO. The first line is not initialising anything, it is simply declaring a data structure which will be used later.

    As the compiler error tells you, the C language does not allow declarations to follow executable statements in a block. Declarations must all appear at the top of the block. So your code will not compiler because it isn't valid C.

    I suggest you look further down for the executable statement which actually initializes the GPIO.

    Hope this helps.

    Chris

Reply
  • 0

    Hi Minh,

    Thanks for your question.

    I think you will find that the first statement "GPIO_InitTypeDef GPIO_InitStructure;" is a declaration, not an executable statement. I assume what you are doing is moving that statement to below the next line, in the hope that this will enable the clock before enabling the GPIO. The first line is not initialising anything, it is simply declaring a data structure which will be used later.

    As the compiler error tells you, the C language does not allow declarations to follow executable statements in a block. Declarations must all appear at the top of the block. So your code will not compiler because it isn't valid C.

    I suggest you look further down for the executable statement which actually initializes the GPIO.

    Hope this helps.

    Chris

Children