/**
* @brief Restore peripheral config before entering DEEPSLEEP mode.
* @param None
* @retval None
*/
static void RestoreConfiguration(void)
{
__IO uint32_t StartUpCounter = 0, HSEStatus = 0;
/* SYSCLK, HCLK, PCLK configuration */
/* Enable HSE */
RCC_HSEConfig( RCC_HSE_ON );
/* Wait till HSE is ready and if Time out is reached exit */
HSEStatus = RCC_WaitForHSEStartUp();
if (HSEStatus == (uint32_t)0x01)
{
/* HCLK = SYSCLK */
RCC_AHBConfig(RCC_SYSCLK_DIV1);
/* PCLK = HCLK */
RCC_APB1Config(RCC_APB1AHB_DIV1);
/* PLL configuration: = HSE * 6 = 48 MHz */
RCC_HSEPREDVConfig(RCC_HSEPREDV1_DIV1);
RCC_PLLConfig(RCC_PLLSOURCE_HSEPREDIV, RCC_GCFGR_PLLMF6);
/* Enable PLL */
RCC_PLL_Enable(ENABLE);
/* PLL as system clock source */
RCC_CK_SYSConfig(RCC_SYSCLKSOURCE_PLLCLK);
}
}
void clk_init(void)
{
// disable external oscillator so we can use pins PF0 , PF1
RCC_HSEConfig(RCC_HSE_OFF);
// this should be enabled already
RCC_HSI_Enable(ENABLE);
// wait for HSI to stabilize
// this is redundant
while( !RCC_GetBitState(RCC_FLAG_HSISTB) );
// this should be enabled already
RCC_CK_SYSConfig(RCC_SYSCLKSOURCE_HSI);
RCC_PLLConfig(RCC_PLLSOURCE_HSI_DIV2 , 18);
RCC_PLL_Enable(ENABLE);
// wait for pll to stablilize
// this is redundant
while( !RCC_GetBitState(RCC_FLAG_PLLSTB) );
RCC_CK_SYSConfig(RCC_SYSCLKSOURCE_PLLCLK);
// wait for clock to change to pll
while ((RCC->GCFGR & (uint32_t)RCC_GCFGR_SCSS) != (uint32_t)RCC_GCFGR_SCSS_PLL);
RCC_AHBConfig(RCC_SYSCLK_DIV1); // config ahb clock divider
RCC_APB1Config(RCC_APB1AHB_DIV1);
RCC_APB2Config(RCC_APB2AHB_DIV1);
}