/** * @brief Reset the RCC clock configuration to the default reset state. * @note The default reset state of the clock configuration is given below: * - HSI ON and used as system clock source * - HSE, PLL, PLLI2S, PLLSAI OFF * - AHB, APB1 and APB2 prescaler set to 1. * - CSS, MCO OFF * - All interrupts disabled * @note This function doesn't modify the configuration of the * - Peripheral clocks * - LSI, LSE and RTC clocks * @retval An ErrorStatus enumeration value: * - SUCCESS: RCC registers are de-initialized * - ERROR: not applicable */ ErrorStatus LL_RCC_DeInit(void) { uint32_t vl_mask = 0xFFFFFFFFU; /* Set HSION bit */ LL_RCC_HSI_Enable(); /* Wait for HSI READY bit */ while(LL_RCC_HSI_IsReady() != 1U) {} /* Reset CFGR register */ LL_RCC_WriteReg(CFGR, 0x00000000U); /* Reset HSEON, HSEBYP, PLLON, CSSON, PLLI2SON and PLLSAION bits */ CLEAR_BIT(vl_mask, (RCC_CR_HSEON | RCC_CR_HSEBYP | RCC_CR_PLLON | RCC_CR_CSSON | RCC_CR_PLLSAION | RCC_CR_PLLI2SON)); /* Write new mask in CR register */ LL_RCC_WriteReg(CR, vl_mask); /* Set HSITRIM bits to the reset value*/ LL_RCC_HSI_SetCalibTrimming(0x10U); /* Wait for PLL READY bit to be reset */ while(LL_RCC_PLL_IsReady() != 0U) {} /* Wait for PLLI2S READY bit to be reset */ while(LL_RCC_PLLI2S_IsReady() != 0U) {} /* Wait for PLLSAI READY bit to be reset */ while(LL_RCC_PLLSAI_IsReady() != 0U) {} /* Reset PLLCFGR register */ LL_RCC_WriteReg(PLLCFGR, 0x24003010U); /* Reset PLLI2SCFGR register */ LL_RCC_WriteReg(PLLI2SCFGR, 0x24003000U); /* Reset PLLSAICFGR register */ LL_RCC_WriteReg(PLLSAICFGR, 0x24003000U); /* Disable all interrupts */ CLEAR_BIT(RCC->CIR, RCC_CIR_LSIRDYIE | RCC_CIR_LSERDYIE | RCC_CIR_HSIRDYIE | RCC_CIR_HSERDYIE | RCC_CIR_PLLRDYIE | RCC_CIR_PLLI2SRDYIE | RCC_CIR_PLLSAIRDYIE); /* Clear all interrupt flags */ SET_BIT(RCC->CIR, RCC_CIR_LSIRDYC | RCC_CIR_LSERDYC | RCC_CIR_HSIRDYC | RCC_CIR_HSERDYC | RCC_CIR_PLLRDYC | RCC_CIR_PLLI2SRDYC | RCC_CIR_PLLSAIRDYC | RCC_CIR_CSSC); /* Clear LSION bit */ CLEAR_BIT(RCC->CSR, RCC_CSR_LSION); /* Reset all CSR flags */ SET_BIT(RCC->CSR, RCC_CSR_RMVF); return SUCCESS; }
/** * @brief Reset the RCC clock configuration to the default reset state. * @note The default reset state of the clock configuration is given below: * - HSI ON and used as system clock source * - HSE and PLL OFF * - AHB and APB1 prescaler set to 1. * - CSS, MCO OFF * - All interrupts disabled * @note This function doesn't modify the configuration of the * - Peripheral clocks * - LSI, LSE and RTC clocks * @retval An ErrorStatus enumeration value: * - SUCCESS: RCC registers are de-initialized * - ERROR: not applicable */ ErrorStatus LL_RCC_DeInit(void) { uint32_t vl_mask = 0U; /* Set HSION bit */ LL_RCC_HSI_Enable(); /* Set HSITRIM bits to the reset value*/ LL_RCC_HSI_SetCalibTrimming(0x10U); /* Reset SW, HPRE, PPRE and MCOSEL bits */ vl_mask = 0xFFFFFFFFU; CLEAR_BIT(vl_mask, (RCC_CFGR_SW | RCC_CFGR_HPRE | RCC_CFGR_PPRE | RCC_CFGR_MCOSEL)); LL_RCC_WriteReg(CFGR, vl_mask); /* Reset HSEON, CSSON, PLLON bits */ vl_mask = 0xFFFFFFFFU; CLEAR_BIT(vl_mask, (RCC_CR_PLLON | RCC_CR_CSSON | RCC_CR_HSEON)); LL_RCC_WriteReg(CR, vl_mask); /* Reset HSEBYP bit */ LL_RCC_HSE_DisableBypass(); /* Reset CFGR register */ LL_RCC_WriteReg(CFGR, 0x00000000U); #if defined(RCC_HSI48_SUPPORT) /* Reset CR2 register */ LL_RCC_WriteReg(CR2, 0x00000000U); /* Disable HSI48 */ LL_RCC_HSI48_Disable(); #endif /*RCC_HSI48_SUPPORT*/ /* Set HSI14TRIM/HSI14ON/HSI14DIS bits to the reset value*/ LL_RCC_HSI14_SetCalibTrimming(0x10U); LL_RCC_HSI14_Disable(); LL_RCC_HSI14_EnableADCControl(); /* Reset CFGR2 register */ LL_RCC_WriteReg(CFGR2, 0x00000000U); /* Reset CFGR3 register */ LL_RCC_WriteReg(CFGR3, 0x00000000U); /* Clear pending flags */ #if defined(RCC_HSI48_SUPPORT) vl_mask = (LL_RCC_CIR_LSIRDYC | LL_RCC_CIR_LSERDYC | LL_RCC_CIR_HSIRDYC | LL_RCC_CIR_HSERDYC | LL_RCC_CIR_PLLRDYC | LL_RCC_CIR_HSI14RDYC | LL_RCC_CIR_HSI48RDYC | LL_RCC_CIR_CSSC); #else vl_mask = (LL_RCC_CIR_LSIRDYC | LL_RCC_CIR_LSERDYC | LL_RCC_CIR_HSIRDYC | LL_RCC_CIR_HSERDYC | LL_RCC_CIR_PLLRDYC | LL_RCC_CIR_HSI14RDYC | LL_RCC_CIR_CSSC); #endif /* RCC_HSI48_SUPPORT */ SET_BIT(RCC->CIR, vl_mask); /* Disable all interrupts */ LL_RCC_WriteReg(CIR, 0x00000000U); return SUCCESS; }
/* * Unconditionally switch the system clock source to HSI. */ __unused static void stm32_clock_switch_to_hsi(u32_t ahb_prescaler) { /* Enable HSI if not enabled */ if (LL_RCC_HSI_IsReady() != 1) { /* Enable HSI */ LL_RCC_HSI_Enable(); while (LL_RCC_HSI_IsReady() != 1) { /* Wait for HSI ready */ } } /* Set HSI as SYSCLCK source */ LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_HSI); LL_RCC_SetAHBPrescaler(ahb_prescaler); while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_HSI) { } }