FAQs
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 

STM32F3xx Clock configuration

freya17365
Associate II

‎2017-01-18 06:48 AM

Posted on January 18, 2017 at 15:48

Hi to all,

this is my first project using a STM32F373 MCU, but I am not able even to let a LED blink.

I assume that system clock is not running as I get no response also enabling the MCO and check it with a scope.

For my clock initialization routine I used the cubemx code as base. Here is my code:

--------------------------------------------------------

/*-------------------------------- HSE - HSI Configuration -----------------------*/
 if(!HSEHSI)
 {
 if(!(RCC->CR & RCC_CR_HSION)) RCC->CR |= RCC_CR_HSION; // If HSI in not ON, just enable it
 while(!(RCC->CR & RCC_CR_HSIRDY));
 RCC->CR &= ~RCC_CR_PLLON; // Disable PLL
 RCC->CFGR &= ~RCC_CFGR_PLLSRC_HSE_PREDIV; // HSI as PLL source
 }
 else
 {
 RCC->CR &= ~RCC_CR_HSEBYP; // Disable HSE_BYPASS
 RCC->CR |= RCC_CR_HSEON; // Enable HSE
 while(!(RCC->CR & RCC_CR_HSERDY)); // Wait for HSE being ready
 RCC->CR &= ~RCC_CR_PLLON; // Disable PLL
 while(RCC->CR & RCC_CR_PLLRDY); // Wait for PLL disabled
 RCC->CFGR |= RCC_CFGR_PLLSRC_HSE_PREDIV; // HSE as PLL source
 RCC->CFGR &= ~RCC_CFGR_PLLXTPRE; // HSE not divided
 RCC->CFGR2 &= (RCC->CFGR2 & ~RCC_CFGR2_PREDIV) | RCC_CFGR2_PREDIV_DIV1; // Input clock not divided
 }
 RCC->CFGR = ((RCC->CFGR & ~RCC_CFGR_PLLMUL) | RCC_CFGR_PLLMUL9); // PLL = 9*HSE
 RCC->CFGR = (RCC->CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_PLL; // PLL as SYSTEM CLOCK
 RCC->CFGR = (RCC->CFGR & ~RCC_CFGR_PLLXTPRE) | RCC_CFGR_PLLXTPRE_HSE_PREDIV_DIV1; // HSE/PREDIV clock not divided for PLL entry
 RCC->CFGR |= RCC_CFGR_USBPRE_DIV1_5; // USB divided by 3
 RCC->CFGR = (RCC->CFGR & ~RCC_CFGR_PPRE2) | RCC_CFGR_PPRE2_DIV1; // APB2 not divided
 RCC->CFGR = (RCC->CFGR & ~RCC_CFGR_PPRE1) | RCC_CFGR_PPRE1_DIV2; // APB1 divided by 2
 RCC->CFGR = (RCC->CFGR & ~RCC_CFGR_HPRE) | RCC_CFGR_HPRE_DIV1; // AHB not divided
 RCC->CFGR2 &= (RCC->CFGR & ~RCC_CFGR_MCO) | RCC_CFGR_MCO_SYSCLK; // Enable MCO
 RCC->CR |= RCC_CR_PLLON; // Enable PLL
 while(!(RCC->CR & RCC_CR_PLLRDY)); // Wait for PLL enabled
// FLASH->ACR = (FLASH->ACR &(~FLASH_ACR_LATENCY)) | FLASH_ACR_LATENCY_2; // Set FLASH latency = 2
 /*-------------------------------- LSE - LSI Configuration -----------------------*/
 if(!LSELSI)
 {
 if(!(RCC->CSR & RCC_CSR_LSION)) RCC->CSR |= RCC_CSR_LSION; //Enable LSI
 while(!(RCC->CSR & RCC_CSR_LSIRDY)); // Wait for LSI ready
 RCC->BDCR = (RCC->BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_LSI; // LSI as RTC clock
 }
 else
 {
 PWR->CR |= PWR_CR_DBP; // Disable RTC write protect
 if(!(RCC->BDCR & RCC_BDCR_LSEON)) RCC->BDCR = (RCC->BDCR & ~RCC_BDCR_LSE) | RCC_BDCR_LSEON; // If LSE in not ON, just enable it
 while(!(RCC->BDCR & RCC_BDCR_LSERDY));
 RCC->BDCR = (RCC->BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_LSE; // LSE as RTC clock
 }
 RCC->CIR = 0x00000000; // Disable all interrupts�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?

--------------------------------------------------------

Someone encountered this problem already?

Do I make some mistakes?

Thank you

Freya

0 Kudos
7 REPLIES 7
Khouloud GARSI
Lead II

‎2017-01-18 07:00 AM

Posted on January 18, 2017 at 16:00

Hi Freya,

I advise you to refer to the 'GPIO_IOToggle' example provided in the

http://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32cube-embedded-software/stm32cubef3.html

package or in

http://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32-standard-peripheral-libraries/stsw-stm32108.html

(

STSW-STM32108) 

under the following paths:
  • STM32Cube_FW_F3_V1.7.0\Projects\STM32373C_EVAL\Examples\GPIO\GPIO_IOToggle (cube)
  • STM32F30x_DSP_StdPeriph_Lib_V1.2.3\Projects\STM32F30x_StdPeriph_Examples\GPIO (SPL)

Khouloud

0 Kudos
waclawek.jan
Guru

‎2017-01-18 07:09 AM

Posted on January 18, 2017 at 16:09

this is my first project using a STM32F373 MCU, but I am not able even to let a LED blink.

Start with blinky with no touching the clocks, running on whatever default clock is after reset.

Only if you get that running, start playing with clocks.

Style advice: don't read-modify-write the registers unless absolutely necessary; prefer direct writes to them.

JW

0 Kudos
freya17365
Associate II
In response to waclawek.jan

‎2017-01-19 01:19 PM

Posted on January 19, 2017 at 21:19

 ,

 ,

Hi to all,

I checked GPIO toggle and used deafult values, but nothing changed, so I reduced my program as much as I could:

--------------------------------------------------------------------------------------------

♯ include 'stm32f3xx.h'

♯ define LED3 , ,  , , ,  ,1 , ,  , , ,  ,//GPIOD

 ,

♯ define LED2 , ,  , , ,  ,2 , ,  , , ,  ,//GPIOD

 ,

♯ define LED1 , ,  , , ,  ,3 , ,  , , ,  ,//GPIOD

 ,

♯ define LED0 , ,  , , ,  ,4 , ,  , , ,  ,//GPIOD

 ,

void SystemInit()

 ,

{

 ,

// , ,  ,if(!(RCC->,CR &, RCC_CR_HSIRDY)) RCC->,CR |= RCC_CR_HSION,

 ,

// , ,  ,while((RCC->,CR &, RCC_CR_HSIRDY) == 0), , ,  ,// Wait for HSI being ready

 ,

 , ,  ,return,

 ,

}

int main(void)

 ,

{

 ,

 , ,  ,if(!(RCC->,AHBENR &, RCC_AHBENR_GPIODEN)) RCC->,AHBENR |= RCC_AHBENR_GPIODEN, , ,  , , ,  ,// Enable GPIOD clock , ,  ,

 ,

// , ,  ,RCC->,AHBENR |= RCC_AHBENR_GPIODEN,

 ,

 , ,  ,

 ,

 , ,  ,GPIOD->,MODER &,= ~(0x03<,<,(2*LED3) | 0x03<,<,(2*LED2) | 0x03<,<,(2*LED1) | 0x03<,<,(2*LED0)), , ,  ,//Alternate function = output

 ,

 , ,  ,GPIOD->,MODER |= 0x01<,<,(2*LED3) | 0x01<,<,(2*LED2) | 0x01<,<,(2*LED1) | 0x01<,<,(2*LED0),

 ,

 , ,  ,GPIOD->,OTYPER &,= ~(0x01<,<,LED2 | 0x01<,<,LED1 | 0x01<,<,LED0), , ,  ,//Output push-pull

 ,

 , ,  ,GPIOD->,OTYPER |= 0x00<,<,LED3 | 0x00<,<,LED2 | 0x00<,<,LED1 | 0x00<,<,LED0,

 ,

 , ,  ,GPIOD->,OSPEEDR &,= ~(0x03<,<,(2*LED3) | 0x03<,<,(2*LED2) | 0x03<,<,(2*LED1) | 0x03<,<,(2*LED0)), , ,  ,//Pin speed = low speed

 ,

 , ,  ,GPIOD->,OSPEEDR |= 0x00<,<,(2*LED3) | 0x00<,<,(2*LED2) | 0x00<,<,(2*LED1) | 0x00<,<,(2*LED0),

 ,

 , ,  ,GPIOD->,PUPDR &,= ~(0x03<,<,(2*LED3) | 0x03<,<,(2*LED2) | 0x03<,<,(2*LED1) | 0x03<,<,(2*LED0)), , ,  ,//No Pull up or Pull Down

 ,

 , ,  ,GPIOD->,PUPDR |= 0x00<,<,(2*LED3) | 0x00<,<,(2*LED2) | 0x00<,<,(2*LED1) | 0x00<,<,(2*LED0),

 ,

 , ,  ,

 ,

 , ,  ,GPIOD->,BSRRL |= 1<,<,LED3 | 1<,<,LED2 | 1<,<,LED1 | 1<,<,LED0,

 , , ,

 ,

 , , , while(1)

 ,

 , ,  ,{  ,

 ,

 , ,  ,}

 ,

}

--------------------------------------------------------------------------------------------

Assuming that clock configuration in automatically set at reset, I configure GPIO pins, but nothing happenes.

Similar code on STM32F030 works, so I do not understand why not here.

Thank you

Freya

0 Kudos
waclawek.jan
Guru

‎2017-01-19 01:52 PM

Posted on January 19, 2017 at 22:52

Looks good. Question is, whether the startup code is OK.

Is this a known good board such as a Nucleo? If not, I'd double-check all ground and all supply pins including VCAPs (measuring the voltage on them and checking against datasheet).

JW

0 Kudos
freya17365
Associate II

‎2017-01-24 11:07 AM

Posted on January 24, 2017 at 20:07

Hi JW,

it is a my own board, not a welll known one.

I tried to modify the code using include files for stm32f0xx MCU's, but leaving startup_stm32f373xc.s as startup file and the programs worked fine.

But every time I try to select stm32f373as MCU, it does not work.

Is it my fault or is it a compiler (Keil) fault?

Do I have to check some settings?

Thank you

Freya
0 Kudos
waclawek.jan
Guru

‎2017-01-24 01:44 PM

Posted on January 24, 2017 at 22:44

I don't understand what did you do, but mixing files intended for different families won't do any good.

The ST-provided startup makes usually calls to routines setting up clocks etc.

/

*

Call

the clock system intitialization function.

*

/

bl

SystemInit

/

*

Call

static constructors

*

/

bl

__libc_init_array

Try to comment them out.

JW

0 Kudos
freya17365
Associate II

‎2017-01-28 08:13 AM

Posted on January 28, 2017 at 17:13

Hi to all,

the problem is partially solved.

I added the following lines:

  /* FPU settings ------------------------------------------------------------*/

  #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)

    SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2));  /* set CP10 and CP11 Full Access */

  #endif

and

 SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */

and now everything works. The remaining part of problem is that MCu works at 36 MHz instead of 72 MHz

Freya

0 Kudos
Top