Hard Fault When I enable the USART3_8_IRQn interrupt.

[stenasc]

Posted on April 18, 2017 at 23:07

Hi Forum,

I'm using the stm32f091, but when I enable the USART3 interrupt, the system hard faults. I already use USARTS1 and 2 without any problem. Not sure what else is required, so I'd be grateful for some assistance. One thing I;d like to know is  how do you distinguish between interrupts from USARTS3 up to USART8.

Kind Regards

Bob

  USART_InitTypeDef USART_InitStructure;

  GPIO_InitTypeDef GPIO_InitStructure;  NVIC_InitTypeDef NVIC_InitStructure;  // Enable GPIOC clock   RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);   // Enable USART3 APB clock   RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);        // Connect pin to Periph  GPIO_PinAFConfig(GPIOC, GPIO_PinSource10, GPIO_AF_1);   //  USART3 TX  GPIO_PinAFConfig(GPIOC, GPIO_PinSource11, GPIO_AF_1);   //  USART3 RX   // Configure pins as AF pushpull   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;  GPIO_Init(GPIOC, &GPIO_InitStructure);        USART_InitStructure.USART_BaudRate = 9600;  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(USART3, &USART_InitStructure);      USART_Cmd(USART3, ENABLE);       //  Enable the COM3 Receive interrupt: this interrupt is generated when the//  COM3 receive data register is not empty   USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);

  // USART3 IRQ Channel configuration

  NVIC_InitStructure.NVIC_IRQChannel = USART3_8_IRQn;   

  NVIC_InitStructure.NVIC_IRQChannelPriority = 1;

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;  NVIC_Init(&NVIC_InitStructure);

[Tesla DeLorean]

Posted on April 19, 2017 at 00:23

You check the status registers of the USART you plan to service. 

[stenasc]

Posted on April 19, 2017 at 01:17

Fair enough regarding the usart article status register but any idea why the hard fault occurs.

Bob

[waclawek.jan]

Posted on April 19, 2017 at 01:25

Make sure the ISR's name matches that in the vector table, typically located with startup code.

JW

[Tesla DeLorean]

Posted on April 19, 2017 at 02:17

Are you sure it is getting a Hard Fault, and not just entering the Default Handler, which is also a while(1) loop?

Check the naming of your IRQHandler, and that it matches, and links properly with the entry in the Vector Table.

[stenasc]

Posted on April 19, 2017 at 14:38

Thanks very much. The interrupt was missing from the vector table. Adding it fixed the issue. Once again many thanks to the forum.

Kind Regards

Bob