STM8S003F3P6 becomes unresponsive and can no longer be programed

[AAtki.1]

Hello,

I'm writing some timer code for the STM8S003F3P6. I am using SDCC to compile it and stm8flash to flash it on to the device with a third part ST-Link V2.

I am having an issue that when I flash the device with my code it doesn't run and I can no longer write to the device. I can still read the flash memory and write to non-program memory but I seem unable to reprogram the device and I'm not sure why. This has also been hard to debug due to having limited numbers of ICs and it hard to buy more of them atm.

Below is the code I am running. It only crashes when I add timer_setcompare(adc_read()); to the main loop. adc_read() works when on its own and just returns a 16 bit value. timer_setcompare() seems to work during the init.

Does anyone have any idea why this would be bricking my devices?

---- Main.c ----
#include "adc.h"
#include "debugPort.h"
#include "stm8s.h"
#include "timer.h"
 
#define wfi() \
	{ __asm__("wfi\n"); } /* Wait For Interrupt */
 
void main() {
	CLK_DIVR	= 0x00;	   // Set the frequency to 16 MHz
	CLK_PCKENR1 = 0xFF;	   // Enable peripherals
 
	unsigned long i = 0;
	uart_init();
	outMsg("\nStarting...\n");
 
	adc_init();
 
	PC_DDR = 0b1000000;
	PC_CR1 = 0b1000000;
	PC_ODR = 0b0000000;
	uint16_t adc = adc_read();
 
	timer_init();
 
	while(1) {
		timer_setcompare(adc_read());
	}
}
---- Timer.c ----
 
#include "adc.h"
#include "stm8s.h"
#include "debugPort.h"
#include "timer.h"
 
#include <stdint.h>
#include <stdbool.h>
#define BitGet(x, n)   (bool) (((x) >> (n)) & 1)
#define enableInterrupts()     {__asm__("rim\n");}
 
const uint16_t tim1_prescaler = 4;
const uint16_t tim1_auto_reload = 1023;
 
void timer_setcompare(uint16_t compare){
    TIM1_CCR1H = (compare >> 8);
    TIM1_CCR1L = (compare & 0xFF);
}
 
void timer_init(void)
{
	FLASH_DUKR = 0xAE;
  	FLASH_DUKR = 0x56;
 
	FLASH_CR2 |= (1 << 7);
	FLASH_NCR2 &= ~(1 << 7);
 
	OPT2 |= (1 << 0);
	NOPT2 &= ~(1 << 0);
 
	outMsg("%X - %X\n", OPT2, NOPT2);
 
	FLASH_IAPSR &= ~(1 << 3);
 
    TIM1_PSCRH = (tim1_prescaler >> 8);
    TIM1_PSCRL =  (tim1_prescaler & 0xFF);
 
    TIM1_ARRH = (tim1_auto_reload >> 8);
    TIM1_ARRL = (tim1_auto_reload & 0xFF);
 
    timer_setcompare(500);
    
    TIM1_RCR = 0;
 
    TIM1_CCER1 = 0b1; //Enable Compare   
    TIM1_CCER1 |= 0b01; //Active Low   
 
    TIM1_CCMR1 = 0b1000; //Enable preload 
    TIM1_CCMR1 |= 0b01100000; //Set PWM Mode 1
 
    TIM1_EGR |= 0b1; // Update event for new register settings
    TIM1_BKR = 0b10000000; //enable output?
 
    TIM1_CR1 = 0b1; //Enable Timer
 
     outMsg("Timer Start Up Done\n");
}

[WilkoL]

Can you still read it with ST_Visual_Programmer? If you can, check the status of the ROP (read out protection).

You can also use it to erase the mcu by setting it, write it and then resetting it. It will do a mass-erase.

About the program, why do you enable interrupts? I do not see an interrupt handler and you do not enable any interrupts on the peripherals. Now, I do not know SDCC so maybe it is handled somewhere else. My experience is that when my code hangs, it is often that I forgot to handle some interrupt.

EDIT: Oh, you do not enable interrupts, it is just a #define , or is it still enabled somewhere else?

[AAtki.1]

Thanks for the reply. Interrupts are not being used. The #define was there for testing other things.

As for using STVP. I can read the option bytes. Only one is set and the one for alternative function for C6.

The good news is I was able to reset unbrick the device by spamming the write device button on the option byte, memory and program file tab (it fails most of the time). So thank you very much for suggesting STVP.

However, I'm still unsure of what caused the issue in the first place.

Edit: Tried to same method a different one I bricked and it doesn't seem to work.

[Tesla DeLorean]

>>However, I'm still unsure of what caused the issue in the first place.

Crashing Early

Breaking the pins used for Debug/SWIM, ie remapping, changing function

Ballsing up the Flash or Options Bytes

?

Perhaps create some more interactive code so it can report what's happening inside the device, dump registers/peripheral, and selectively changing internal settings, or running different function tests.

[WilkoL]

His code doesn't seem to (want to) change the function of the SWIM pin, and he could access the mcu with STVP. My guess would be an instable powersupply during programming. Other than that... nu clue.

[WilkoL]

Did you try to set the ROP bit, save it and then reset it and save again?