stm32f405 strange behavior

[Angelo1]

Posted on April 03, 2014 at 18:16

Dear,

i am proceeding over a development of a quiet simple application (23K of code now), increasing complexity, everything was working fine, but from some recent code improvements and builds, i started to have the application behavior corrupted. I am driving am SSD1289 lcd / touch, and driving also some gpio. Increasing the code size, LCD started to be non responsive to the graphic commands, so i commented out the great part of the code, and let only a small code working. If i just init the gpio, and make a relay click on and off each second, it works.

/**
* @brief This function handles SysTick Handler.
* @param None
* @retval None
*/
void SysTick_Handler(void)
{
delay_decrement();
prescaler--;
if(prescaler == 0)
{
prescaler = 200;
}
}

void delay_decrement(void) { if (time_preload != 0x00) time_preload--; } void delay_ms(volatile uint32_t t) { time_preload = t; while(time_preload != 0); }

void run ()
{
for(;;)
{
gpio_relay_on_off(i);
i=!i;
delay_ms(1000);
}
}

But, if i start to enable the FSMC controller, with the line: RCC_AHB3PeriphClockCmd(RCC_AHB3Periph_FSMC, ENABLE); Then i hear the relay clicking on or off each 4 seconds. Very strange. Could i have some hardware issue ? Many thanks Angelo

[Tesla DeLorean]

Posted on April 03, 2014 at 18:36

Could i have some hardware issue ?

Or a software one. Or one with your linker script.

[Angelo1]

Posted on April 03, 2014 at 18:58

Dear Clive,

solved, seems it was another issue in the linker script, on the .data section, for the remapping flash ''.data'' to ram.

These because i am using gcc toolchain, and i found a starting linker script that i extended.

A professor at my school was saying ''ok to copy, but understanding !''. Now as a punishment i study well the linker script, i have to make it mine.

Ciao

Angelo

[Tesla DeLorean]

Posted on April 03, 2014 at 19:44

In the other thread I pointed to a project that uses GNU/GCC and has a functional linker script.

Linker Scripts (or Scatter Files, in Keil nomenclature) are complex beasts, I tend to find many examples and understand them, and adapt them as required. I have a background in linkers/loaders, and the GNU linker is far more inflexible than others that target embedded explicitly, ie split roms, or sparse memory maps.

The complexity in ROM/FLASH based systems is that the start up code must initialize and copy things to RAM (unpack itself), rather than an executable file format, which paints each memory area explicitly.