code crashes and lead to Hardfault when I include I2C1_IRQ_handler.

[GR.5]

Hi guys,

I using 

keil uvisionV5.35.0.0

arm_compiler : V6.16

We are developing a project on STM32L071CZYx MCU. which has 

flash memory: 192kB

RAM: 20KB

I have attached a I2C1_IRQhandler function for your reference.

void I2C1_IRQHandler(void)
{
		I2C1->CR1 &= ~(I2C_CR1_RXIE |I2C_CR1_ADDRIE | I2C_CR1_STOPIE | I2C_CR1_TXIE);
		switch((I2C1->ISR &(I2C_ISR_STOPF | I2C_ISR_ADDR |I2C_ISR_RXNE | I2C_ISR_TXIS)))
		{
			case 0x08: //address match
				dev_addr = ((I2C1->ISR >> 16 ) & 0xFE); // assigning Recieved slave address
				if(I2C1->ISR & I2C_ISR_DIR)
					{
						// Slave address with Read bit
						if(i2c_state == I2C_GOT_CONTROL_WORD_ADDR)
						{
							i2c_state = I2C_REPEATED_START;
						}
						else 
						{
							i2c_state = I2C_RD_STARTED;
						}
						__HAL_I2C_CLEAR_FLAG(&hi2c1,(I2C_FLAG_ADDR ));
						I2C1->CR1 |= (I2C_CR1_TXIE); // enabling Transmitter Interrupt
						//slave Tx
					}
				else
					{
						// Slave address with write bit
						i2c_pkt_length = 0;
						
						i2c_state = I2C_WR_STARTED;
						__HAL_I2C_CLEAR_FLAG(&hi2c1,I2C_FLAG_ADDR);
						I2C1->CR1 |= (I2C_CR1_RXIE); // stopIE is not required
						//slave Rx
						} 
			break;
			case 0x04: //rx data for master
				if(i2c_state == I2C_WR_STARTED)
				{
					CW =I2C1->RXDR;
					word_addr = CW;
					i2c_state = I2C_GOT_CONTROL_WORD_ADDR;
				}
				else
				{
					i2cdatarx[i2c_pkt_length++] = I2C1->RXDR;
					i2c_state = I2C_DATA_STARTED;
				}
				__HAL_I2C_CLEAR_FLAG(&hi2c1,I2C_FLAG_RXNE);
			I2C1->CR1 |= (I2C_CR1_RXIE | I2C_CR1_ADDRIE | I2C_CR1_STOPIE); // enabling Rx address match and Stop interrupt
			break;
			
			case 0x20: // detected a stop
				if (dev_addr == 0xB0 )
				{
					if (i2c_state == I2C_DATA_STARTED || i2c_state == I2C_GOT_CONTROL_WORD_ADDR)
					{
						F0_write(word_addr);
					}
					else 
					{
					I2C1->ISR |= I2C_ISR_TXE;//Setting flushing the TX buffer for new data transfer
					}
				}
				else
				{
					if (i2c_state == I2C_DATA_STARTED || i2c_state == I2C_WR_STARTED)
					{
						if (mode == mFACTORY)
						{
							A0_write_FM(word_addr); // writting to sram and Eeprom
						}
						else
						{
							A0_write(word_addr);
						}
					}
					else 
					{
					I2C1->ISR |= I2C_ISR_TXE;//Setting flushing the TX buffer for new data transfer
					}
				}
				i2c_state = I2C_IDLE;
				__HAL_I2C_CLEAR_FLAG(&hi2c1,I2C_FLAG_STOPF);
				I2C1->CR1 |= (I2C_CR1_ADDRIE); // enabling address match 
			break;
			case 0x02: // Transmit has detected
					
					//i2cdatarx = I2C_read_F0(CW);
					if (dev_addr == 0xB0)
					{
						I2C1->TXDR = F0_Read(CW);
					}
					else
					{
						if (mode == 1)
							{
						I2C1->TXDR = A0_read_FM(CW);
							}
						else
							{
							I2C1->TXDR = A0_read(CW);	
							}
					}
				__HAL_I2C_CLEAR_FLAG(&hi2c1,(I2C_FLAG_ADDR));
				I2C1->CR1 |= (I2C_CR1_STOPIE | I2C_CR1_TXIE);
			break;
		}
}

here I2C1 is configured has a slave.

without I2C_IRQ_handler function I2C1 will work well in polling mode.

Code crashes and lead to hardfault at hsc_dev_obj_init when I include I2C1_IRQ_handler function.

I have tried all the ways like increasing stack memory and reducing global variables but nothing works. please help me to resolve this error.

Regards,

Gopal Gowda

[Foued_KH]

Hello @GR.5​ ,

Please check the LR register content (in CPU registers), if :

• 0xFFFF-FFF1: Handler stack  
• 0xFFFF-FFF9 : main stack 
• 0xFFFF-FFFD : process stack 

If main stack => copy the @ in the main stack register and paste it in the memory view .

Copy the PC content and paste it in the disassembly viewer and see the instruction that cause the HardaFault 

Foued

[GR.5]

Hi KHALSI_Foued Thanks for your reply,

As we can see above the LR register value is 0xFFFF-FFF9 and call stack local is showing hsc_dev_obj_init lead to the hardfault your suggesting that there is problem in handling main stack (may be stack overflow) so I have tried to increase the stack size and reduce the global variables in the program but still not working.

I don't know how I2C1_IRQ_handler is causing the problem?

Regards,

Gopal Gowda

[Tesla DeLorean]

Have a better routine to display registers at fault, and identify specific instructions involved.​

[GR.5]

Hi Tesla thanks for your reply,

I have attached a function at which I am getting Hardfault.

hsc_dev_t* hsc_dev_obj_init(struct hsc_dev_cls *dev, uint32_t asic_id)
{
 /* Initialize */
 HSC_MEMSET(dev, 0x0, sizeof(struct hsc_dev_cls));
 dev->ops = NULL;
 dev->asic_id = asic_id;
 dev->pkg_type = 0;
 
 return (hsc_dev_t*) dev;
}

But there won't be any crash in code if I don't add I2C1_IRQhandler function

only when I include I2C1_IRQhandler function It crashes.

 I don't know How I2C1_IRQhandler function is responsible for crash.

Regards,

Gopal Gowda

[Tesla DeLorean]

Sanity check the pointer "dev", ie its not NULL, misaligned, pointing outside of RAM

[GR.5]

Hi Krani thank you for reply,

can u elaborate please.

do you mean to display all the registers like R0 R1 R2 R3 R12 LR SP PC registers in the hard fault function.?

In Debug mode I executed step by step instructions when I try to execute

dev->ops = NULL of hsc_dev_obj_init function it is leading to hardfault.

[Bob S]

Search these forums, or even the Keil website for fault handler code. @Community member​ has posted several (many????) of them here. Not just CPU registers but the memory management/fault registers.

Hmmm... I've never used uVision on ARM chips, but doesn't it have a fault analysis window somewhere in their IDE?

[Tesla DeLorean]

It does have something, not sure I've learned how to drive it. I know the MCU, I know my code, and I know what I'm looking for..

But, having useful output to a serial port is a force multiplier, it can be used to diagnose failures in the field, using very simple tools, and on large blocks of soak-test units it doesn't require debuggers/pods and infrastructure to the same degree to monitor/log units.

On a good day it can bracket the offending instruction, and I don't even need specific source

https://github.com/cturvey/RandomNinjaChef/blob/main/KeilHardFault.c