Posted on December 22, 2011 at 14:04Hello,
I'm truing to use STM32F217 and CS4344 for my audio application.
I have problem with clock initialization.
/* Enable HSE */
RCC->CR |= ((uint32_t)RCC_CR_HSEON);
/* Wait till HSE is ready and if Time out is reached exit */
do
{
HSEStatus = RCC->CR & RCC_CR_HSERDY;
StartUpCounter++;
} while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSERDY) != RESET)
{
HSEStatus = (uint32_t)0x01;
}
else
{
HSEStatus = (uint32_t)0x00;
}
if (HSEStatus == (uint32_t)0x01)
{
/* HCLK = SYSCLK / 2*/
RCC->CFGR |= RCC_CFGR_HPRE_DIV2;
/* PCLK2 = HCLK / 1*/
RCC->CFGR |= RCC_CFGR_PPRE2_DIV1;
/* PCLK1 = HCLK / 2*/
RCC->CFGR |= RCC_CFGR_PPRE1_DIV2;
/* Configure the main PLL */
RCC->PLLCFGR = PLL_M | (PLL_N << 6) | (((PLL_P >> 1) -1) << 16) |
(RCC_PLLCFGR_PLLSRC_HSE) | (PLL_Q << 24);
/* Enable the main PLL */
RCC->CR |= RCC_CR_PLLON;
/* Wait till the main PLL is ready */
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}
/* Configure Flash prefetch, Instruction cache, Data cache and wait state */
FLASH->ACR = FLASH_ACR_PRFTEN |FLASH_ACR_ICEN |FLASH_ACR_DCEN |FLASH_ACR_LATENCY_1WS;
/* Select the main PLL as system clock source */
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= RCC_CFGR_SW_PLL;
/* Wait till the main PLL is used as system clock source */
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL);
{
}
}
else
{ /* If HSE fails to start-up, the application will have wrong clock
configuration. User can add here some code to deal with this error */
}
/******************************************************************************/
/* I2S clock configuration (For devices Rev B and Y) */
/******************************************************************************/
/* PLLI2S clock used as I2S clock source */
RCC->CFGR &= ~RCC_CFGR_I2SSRC;
/* Configure PLLI2S */
RCC->PLLI2SCFGR = (PLLI2S_N << 6) | (PLLI2S_R << 28);
/* Enable PLLI2S */
RCC->CR |= ((uint32_t)RCC_CR_PLLI2SON);
/* Wait till PLLI2S is ready */
/*while((RCC->CR & RCC_CR_PLLI2SRDY) == 0)
{
}*/
Program hangs on last (commented) while.
Why?
Regards,
Marcin
