STM32 || Unable to initialise interrupts || Nucleo - F746ZG - driver

Question

I am new to the world of STM32 MCU's so please bear with me.
I am following a tutorial on Udemy and trying to write a GPIO interrupt code from scratch. I have done all register configurations and config is working fine as seen through SFR view in debug mode but when I run the code it seems like the interrupt is not enabled. The code never comes in the handler function.
/*
* 003button_interrupt.c
*/
#include <string.h>
#include "stm32f746xx.h"
void delay(void){
for(uint32_t i=0; i<100000; i++);
}
int main(){
GPIO_PeriClockControl(GPIOC,ENABLE);
GPIO_PeriClockControl(GPIOB,ENABLE);
GPIO_Handle_t LED, BTN;
memset(&LED, 0, sizeof(LED));
memset(&BTN, 0, sizeof(BTN));
LED.pGPIOx = GPIOB;
LED.GPIO_PinConfig.GPIO_PinNumber = GPIO_PIN_NO_14;
LED.GPIO_PinConfig.GPIO_PinMode = GPIO_MODE_OUT;
LED.GPIO_PinConfig.GPIO_PinOPType = GPIO_OP_TYPE_PP;
LED.GPIO_PinConfig.GPIO_PinSpeed = GPIO_SPEED_VERY_HIGH;
LED.GPIO_PinConfig.GPIO_PinPuPdControl = GPIO_NO_PUPD;
GPIO_Init(&LED);
LED.pGPIOx = GPIOB;
LED.GPIO_PinConfig.GPIO_PinNumber = GPIO_PIN_NO_7;
LED.GPIO_PinConfig.GPIO_PinMode = GPIO_MODE_OUT;
LED.GPIO_PinConfig.GPIO_PinOPType = GPIO_OP_TYPE_PP;
LED.GPIO_PinConfig.GPIO_PinSpeed = GPIO_SPEED_VERY_HIGH;
LED.GPIO_PinConfig.GPIO_PinPuPdControl = GPIO_NO_PUPD;
GPIO_Init(&LED);
BTN.pGPIOx = GPIOC;
BTN.GPIO_PinConfig.GPIO_PinNumber = GPIO_PIN_NO_13;
BTN.GPIO_PinConfig.GPIO_PinMode = GPIO_MODE_IT_FT;
BTN.GPIO_PinConfig.GPIO_PinSpeed = GPIO_SPEED_VERY_HIGH;
BTN.GPIO_PinConfig.GPIO_PinPuPdControl = GPIO_PIN_PU;
GPIO_Init(&BTN);
//IRQ interrupt and priority configuration
GPIO_IRQPriorityConfig(IRQ_NO_EXTI10_15,NVIC_IRQ_PRIO_15);
GPIO_IRQIntConfig(IRQ_NO_EXTI10_15,ENABLE);
while(1);
}
void EXTI15_10_IRQHandler(void){
delay();
GPIO_IRQHandling(GPIO_PIN_NO_13);
GPIO_ToggleOutputPin(GPIOB,GPIO_PIN_NO_14);
GPIO_ToggleOutputPin(GPIOB,GPIO_PIN_NO_7);
}
/*
* stm32f746xx_gpio_driver.c
*/
#include "stm32f746xx_gpio_driver.h"
/*
* peripheral clock setup
*/
void GPIO_PeriClockControl(GPIO_RegDef_t *pGPIOx, uint8_t EnOrDis){
if(EnOrDis == ENABLE){
if(pGPIOx == GPIOA){
GPIOA_PCLK_EN();
}else if(pGPIOx == GPIOB){
GPIOB_PCLK_EN();
}else if(pGPIOx == GPIOC){
GPIOC_PCLK_EN();
}else if(pGPIOx == GPIOD){
GPIOD_PCLK_EN();
}else if(pGPIOx == GPIOE){
GPIOE_PCLK_EN();
}else if(pGPIOx == GPIOF){
GPIOF_PCLK_EN();
}else if(pGPIOx == GPIOG){
GPIOG_PCLK_EN();
}else if(pGPIOx == GPIOH){
GPIOH_PCLK_EN();
}else if(pGPIOx == GPIOI){
GPIOI_PCLK_EN();
}else if(pGPIOx == GPIOJ){
GPIOJ_PCLK_EN();
}else if(pGPIOx == GPIOK){
GPIOK_PCLK_EN();
}
} else {
if(pGPIOx == GPIOA){
GPIOA_PCLK_DIS();
}else if(pGPIOx == GPIOB){
GPIOB_PCLK_DIS();
}else if(pGPIOx == GPIOC){
GPIOC_PCLK_DIS();
}else if(pGPIOx == GPIOD){
GPIOD_PCLK_DIS();
}else if(pGPIOx == GPIOE){
GPIOE_PCLK_DIS();
}else if(pGPIOx == GPIOF){
GPIOF_PCLK_DIS();
}else if(pGPIOx == GPIOG){
GPIOG_PCLK_DIS();
}else if(pGPIOx == GPIOH){
GPIOH_PCLK_DIS();
}else if(pGPIOx == GPIOI){
GPIOI_PCLK_DIS();
}else if(pGPIOx == GPIOJ){
GPIOJ_PCLK_DIS();
}else if(pGPIOx == GPIOK){
GPIOK_PCLK_DIS();
}
}
}
/*
* init and deInit
*/
void GPIO_Init(GPIO_Handle_t *pGPIOHandle){
uint32_t temp = 0;
if(pGPIOHandle->GPIO_PinConfig.GPIO_PinMode <= GPIO_MODE_ANALOG){
temp = (pGPIOHandle->GPIO_PinConfig.GPIO_PinMode << (2* pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber));
pGPIOHandle->pGPIOx->MODER &= ~(0x03 << pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber); // clearing ; always clear before setting
pGPIOHandle->pGPIOx->MODER |= temp; // setting
} else {
// 1. configure RTSR / FTSR
if(pGPIOHandle->GPIO_PinConfig.GPIO_PinMode == GPIO_MODE_IT_FT){
(*EXTI).FTSR |= (1<<pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber);
(*EXTI).RTSR &= ~(1<<pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber); // coz we only want FT, clear the corresponding RTSR bit; just to be safe if it is not already cleared for some reason
} else if(pGPIOHandle->GPIO_PinConfig.GPIO_PinMode == GPIO_MODE_IT_RT){
(*EXTI).RTSR |= (1<<pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber);
(*EXTI).FTSR &= ~(1<<pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber);
} else if(pGPIOHandle->GPIO_PinConfig.GPIO_PinMode == GPIO_MODE_IT_RFT){
(*EXTI).RTSR |= (1<<pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber);
(*EXTI).FTSR |= (1<<pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber);
}
// 2. config the gpio port selection in SYSCFG_EXTICR
uint8_t temp1 = pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber / 4;
uint8_t temp2 = pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber % 4;
uint8_t portcode = GPIO_BASEADDR_TO_CODE(pGPIOHandle->pGPIOx);
SYSCFG_PCLK_EN();
(*SYSCFG).EXTICR[temp1] = portcode << (temp2 * 4);
// 3. enable the exti interrupt delivery using IMR
(*EXTI).IMR |= (1<<pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber);
}
temp = 0;
temp = (pGPIOHandle->GPIO_PinConfig.GPIO_PinSpeed << (2* pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber));
pGPIOHandle->pGPIOx->OSPEEDR &= ~(0x03 << pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber); // clearing
pGPIOHandle->pGPIOx->OSPEEDR |= temp; // setting
temp = 0;
temp = (pGPIOHandle->GPIO_PinConfig.GPIO_PinPuPdControl << (2* pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber));
pGPIOHandle->pGPIOx->PUPDR &= ~(0x03 << pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber); // clearing
pGPIOHandle->pGPIOx->PUPDR |= temp; // setting
temp = 0;
temp = (pGPIOHandle->GPIO_PinConfig.GPIO_PinOPType << (pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber));
pGPIOHandle->pGPIOx->OTYPER &= ~(0x01 << pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber); // clearing
pGPIOHandle->pGPIOx->OTYPER |= temp; // setting
temp = 0;
if(pGPIOHandle->GPIO_PinConfig.GPIO_PinMode == GPIO_MODE_ALTFN){
uint8_t temp1 = pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber / 8;
uint8_t temp2 = pGPIOHandle->GPIO_PinConfig.GPIO_PinNumber % 8;
pGPIOHandle->pGPIOx->AFR[temp1] &= ~(0x0f << (4* temp2)); // clearing
pGPIOHandle->pGPIOx->AFR[temp1] |= pGPIOHandle->GPIO_PinConfig.GPIO_PinAltFunMode << (4* temp2); // setting
}
}
void GPIO_DeInit (GPIO_RegDef_t *pGPIOx){
if(pGPIOx == GPIOA){
GPIOA_REG_RESET();
}else if(pGPIOx == GPIOB){
GPIOB_REG_RESET();
}else if(pGPIOx == GPIOC){
GPIOC_REG_RESET();
}else if(pGPIOx == GPIOD){
GPIOD_REG_RESET();
}else if(pGPIOx == GPIOE){
GPIOE_REG_RESET();
}else if(pGPIOx == GPIOF){
GPIOF_REG_RESET();
}else if(pGPIOx == GPIOG){
GPIOG_REG_RESET();
}else if(pGPIOx == GPIOH){
GPIOH_REG_RESET();
}else if(pGPIOx == GPIOI){
GPIOI_REG_RESET();
}else if(pGPIOx == GPIOJ){
GPIOJ_REG_RESET();
}else if(pGPIOx == GPIOK){
GPIOK_REG_RESET();
}
}
/*
* data read and write
*/
uint8_t GPIO_ReadFromInputPin(GPIO_RegDef_t *pGPIOx, uint8_t PinNumber){
uint8_t value;
value = (uint8_t)((pGPIOx->IDR >> PinNumber) & 0x00000001);
return value;
}
uint16_t GPIO_ReadFromInputPort(GPIO_RegDef_t *pGPIOx){
uint16_t value;
value = pGPIOx->IDR;
return value;
}
void GPIO_WriteToOutputPin(GPIO_RegDef_t *pGPIOx, uint8_t PinNumber, uint8_t value){
if(value == GPIO_PIN_SET){
pGPIOx->ODR |= (1 << PinNumber);
} else if(value == GPIO_PIN_CLEAR || value == GPIO_PIN_RESET){
pGPIOx->ODR &= ~(1 << PinNumber);
}
}
void GPIO_WriteToOutputPort(GPIO_RegDef_t *pGPIOx, uint16_t value){
pGPIOx->ODR = value;
}
void GPIO_ToggleOutputPin(GPIO_RegDef_t *pGPIOx, uint8_t PinNumber){
pGPIOx->ODR ^= (1 << PinNumber);
}
/*
* IRQ configuration and ISR handling
*/
// IRQConfig is for config in processor side
void GPIO_IRQIntConfig(uint16_t IRQNumber, uint8_t EnOrDis){
if(EnOrDis == ENABLE){
// *(NVIC_ISER0 + (((uint32_t)(int32_t)IRQNumber) >> 5UL)) = (uint32_t)(1UL << (((uint32_t)(int32_t)IRQNumber) & 0x1FUL));
if(IRQNumber <= 31){
(*NVIC_ISER0) |= (1<<IRQNumber);
} else if((IRQNumber > 31) && (IRQNumber <= 63)){
(*NVIC_ISER1) |= (1<<(IRQNumber%32));
} else if((IRQNumber > 63) && (IRQNumber <= 95)){
(*NVIC_ISER2) |= (1<<(IRQNumber%64));
} else if(IRQNumber > 95){
(*NVIC_ISER3) |= (1<<(IRQNumber%96));
}
} else if (EnOrDis == DISABLE){
if(IRQNumber <= 31){
(*NVIC_ICER0) |= (1<<IRQNumber);
} else if((IRQNumber > 31) && (IRQNumber <= 63)){
(*NVIC_ICER1) |= (1<<(IRQNumber%32));
} else if((IRQNumber > 63) && (IRQNumber <= 95)){
(*NVIC_ICER2) |= (1<<(IRQNumber%64));
} else if(IRQNumber > 95){
(*NVIC_ICER3) |= (1<<(IRQNumber%96));
}
}
}
void GPIO_IRQPriorityConfig(uint16_t IRQNumber, uint16_t IRQPriority){
// 1. find the ipr register and section
uint32_t iprx = IRQNumber / 4;
uint32_t iprx_section = IRQNumber % 4;
// 2. store the value
uint8_t shift_value = (8*iprx_section) + (8-NO_IPR_BITS_IMPLEMENTED); // need to move more by (8-NO_IPR_BITS_IMPLEMENTED) bits, since not all of 8 bits are used..
uint16_t temp = (IRQPriority << shift_value);
*(NVIC_IPR_BASEADDR + iprx) |= temp; // iprx is multiplied by 4 because each address jump is of 4 bytes..
}
void GPIO_IRQHandling(uint8_t PinNumber){
// clear the exti pr register bit corresponding to the pin number
if((*EXTI).PR & (1<<PinNumber)){
(*EXTI).PR |= ( 1 << PinNumber );
}
}
Please help me find the issue.
Thanks!

Answer 1

The code is barely readable. And it uses some really wild stuff for a beginner. Honestly, I don't think this is a good course as a starting point, it feels unnesessarily complicated for being an intro. I hate to admit it, but I also used one course to get basic general feeling of things before I figured out how to figure things out using documentation - the most important skill (and the course helped with just that; it was also a Udemy course - but hey, information is information, no matter where it comes from).
Back to the topic. It's hard to make head or tails of your code, especially if an error is in some detail. Please, indicate clearly what code you just copy-pasted from some source and what code is your own creation. If there is copied code, the problem is more likely to be in your own code, since you're probably not the first person to use that code. At first glance, the code mentions all parts there are to mention:
You set up GPIO properties.
You set up EXTI peripheral, where you select what pins you want to trigger interrupts.
You set up SYSCFG, where you tell what port that EXTI pin refers to (that pin 14 means GPIOB 14 and not GPIOC 14).
You enable NVIC
If your interrupt is not firing, then looking at SFR absolutely MUST show something. Since you already know how to operate debug mode, it must be something you overlooked there.
I have noticed you're not activating clock for SYSCFG, which binds GPIO ports to EXTI interrupt pins. You can check if SYSCFG is running using two things:
Open SFR in debug mode. If all registers of SYSCFG are 0x00, it's sus. Probably its clock is not running.
Open SFR in debug mode. Open RCC -> APB2ENR, bit SYSCFGEN must be set.
In order to set that bit, do RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN; next to GPIO clock activation (or find how to set that bit with the library you have)