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Problem with the interrupt of UART4 of processor STM32F072CBT6

Question asked by henrique.willian on Nov 22, 2015
Latest reply on Jun 11, 2017 by waclawek.jan

hello,

I'm having a problem with the UART4 of the processor STM32F072CBT6 when the interrupt of the UART is enabled.
Lets me shot the code:

#include "stm32f0xx.h"
#include "stm32f0xx.h"
#include "stm32f0xx_usart.h"
#include "stm32f0xx_misc.h"

void initUSART(void);
void sendStringUart(char *data);
void sendCharUart(char data);


volatile char receiverBufferUart[256];
int possitionUart; //possition of next byte of receiveerBuffer

void initUSART(){

  USART_InitTypeDef USART_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
   
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART4, ENABLE);
 
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_4);
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource1, GPIO_AF_4);
   
  /* Configure USART4 pins:  Rx and Tx ----------------------------*/
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_0 | GPIO_Pin_1;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
 
  /* Enable USART4 IRQ */
  NVIC_InitStructure.NVIC_IRQChannel = USART3_4_IRQn;//USART1_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
   
  USART_InitStructure.USART_BaudRate = 115200;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_Parity = USART_Parity_No;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
 

  USART_Init(USART4, &USART_InitStructure);
  // Habilita a interrupcao
  USART_ITConfig(USART4, USART_IT_RXNE, ENABLE);

  USART_Cmd(USART4,ENABLE);  
}

void sendCharUart(char data){

  while (USART_GetFlagStatus(USART4, USART_FLAG_TXE) == RESET);
  USART_SendData(USART4, data);

}

void sendStringUart(char *data){
    
    int i=0;
    for(;data[i] !=0 ;i++){
        sendCharUart(data[i]);
    }
}

void USART3_4_IRQHandler(void)
{
  /* RXNE handler */
  if(USART_GetITStatus(USART4, USART_IT_RXNE) != RESET)
  {
      receiverBufferUart[possitionUart] = USART_ReceiveData(USART4);
  }    
}
int main(void){


    initUSART();

    sendStringUart("hello world\n");
    while(1);
    return 0;
}

When I execute this code the processor broke in the function HardFault_Handler () at stm32f0xx_it.c:67 - I discovery it using the GDB. However when I comment the line   USART_ITConfig(USART4, USART_IT_RXNE, ENABLE); it work very well, but without interrupt.

Anyone was this problem?
Is some bug of the processor? My code is wrong?

Sorry for my bad English.
Thanks

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