HSI Clock Configuraion

Posted on January 28, 2013 at 22:38

Hi,

I'm using stm32f10xc4, low density value line, it supports an HSE of 8 MHz, my hardware has 20 MHz which is wrong and that's the reason why the clock configuration doesn't go properly - i guess -.

So i tried to get the HSI through the PLL, the target is to reach 24MHz.

Here's my code, but it still doesn't work!

/* Enable Internal High Speed oscillator */

RCC_HSICmd(ENABLE);

/* Set PLL clock output to 24MHz using HSI (8MHz) as entry clock */

RCC_PLLConfig(RCC_PLLSource_HSI_Div2, RCC_PLLMul_6);

/* Select the PLL as system clock source */

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

/* Enable the PLL */

RCC_PLLCmd(ENABLE);

/* Output PLL clock divided by 2 on MCO pin */

RCC_MCOConfig(RCC_MCO_PLLCLK_Div2);

/* Configure HCLK such as HCLK = SYSCLK */

RCC_HCLKConfig(RCC_SYSCLK_Div1);

/* Configure PCLK1 such as PCLK1 = HCLK/2 */

RCC_PCLK1Config(RCC_HCLK_Div1);

/* Configure PCLK2 such as PCLK2 = HCLK */

RCC_PCLK2Config(RCC_HCLK_Div1);

/* Configure ADCCLK such as ADCCLK = PCLK2/2 */

RCC_ADCCLKConfig(RCC_PCLK2_Div2);

The while(1) inside main contains this:

GPIO_WriteBit(GPIOB, GPIO_Pin_0, Bit_SET);

GPIO_WriteBit(GPIOB, GPIO_Pin_0, Bit_RESET);

to measure the frequency, i'm exposing PB.0 to scope.

I tried to use this one but didn't work out either, gave me an unavailable item when watched.

RCC_ClocksTypeDef RCC_Clocks;

RCC_GetClocksFreq(&RCC_Clocks);

Any idea?

Thanks

#hsi #stm32 #clock