Problem with the interrupt of UART4 of processor STM32F072CBT6

willian2005 · ‎2015-11-22

Posted on November 22, 2015 at 21:54

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_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

Note: this post was migrated and contained many threaded conversations, some content may be missing.

waclawek.jan · ‎2017-06-08

Posted on June 08, 2017 at 14:50

OK so it DOES stop on the breakpoint in the ISR when the interrupt happens; and then gets to hardfault while processing the ISR?

JW

Antonio Giovanini · ‎2017-06-08

Posted on June 08, 2017 at 15:01

It never stops on the ISR breakpoint, when the interruption raises, it goes to the 0x0800be00 directly, I have a breakpoint there, if I remove the breakpoint (or click on 'continue') it goes to hardfaul, but it is normal, as it will try to process a wrong instruction, as I have nothing there (0x0800be00).

For information, in another test, I created a new section on 0x0800be00 (with a jump to the correct ISR), but it also goes to the hardfault. I did not understand this behavior yet.

waclawek.jan · ‎2017-06-08

Posted on June 08, 2017 at 15:06

More hummm.

I'd perhaps have a look also at the system memory's vector table/ISR.

JW