Posted on October 06, 2010 at 10:18As far as I can see from your magic numbers you don't select the PLL as system clock. You can try something like this (it seems to work but I don't know if it's the correct way to do it)
//// Configure system clock PLL*3 driven by external high speed
//// oscillator (8 MHz crystall) 24MHz
// Turn on high speed external oscillator
RCC->CR |= RCC_CR_HSEON;
// Wait until it's ready
while ((RCC->CR & RCC_CR_HSERDY) == 0)
;
// Select PREDIV1 as PLL source and sett PLL mul to 3 (set bit 0)
// for 8*3 = 24 MHz
RCC->CFGR |= RCC_CFGR_PLLSRC | RCC_CFGR_PLLMULL_0;
// Start PLL
RCC->CR |= RCC_CR_PLLON;
// Wait until it's ready
while ((RCC->CR & RCC_CR_PLLRDY) == 0)
;
// Select PLL as system clock
RCC->CFGR |= RCC_CFGR_SW_PLL;
// Here we can check if PLL is used, and maybe disable HSI
// Disable HSI
RCC->CR &= ~RCC_CR_HSION;
(Is there some kind of code tags one can use?)
