/*!
    \file  gd32f4xx_rcu.c
    \brief RCU driver
*/

/*
    Copyright (C) 2016 GigaDevice

    2016-08-15, V1.0.1, firmware for GD32F4xx
*/

#include "gd32f4xx_rcu.h"

#define SEL_IRC16M                  0U
#define SEL_HXTAL                   1U
#define SEL_PLLP                    2U
#define OSC_STARTUP_TIMEOUT         ((uint16_t)0xfffffU)
#define LXTAL_STARTUP_TIMEOUT       ((uint16_t)0x3ffffffU)

/*!
    \brief      deinitialize the RCU
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_deinit(void)
{
    /* enable IRC16M */
    RCU_CTL |= RCU_CTL_IRC16MEN;
    rcu_osci_stab_wait(RCU_IRC16M);
    /* reset CFG0 register */
    RCU_CFG0 &= ~(RCU_CFG0_SCS | RCU_CFG0_AHBPSC | RCU_CFG0_APB1PSC | RCU_CFG0_APB2PSC |
                  RCU_CFG0_RTCDIV | RCU_CFG0_CKOUT0SEL | RCU_CFG0_I2SSEL | RCU_CFG0_CKOUT0DIV |
                  RCU_CFG0_CKOUT1DIV | RCU_CFG0_CKOUT1SEL);
    /* reset CTL register */
    RCU_CTL &= ~(RCU_CTL_HXTALEN | RCU_CTL_CKMEN | RCU_CTL_PLLEN | RCU_CTL_PLLI2SEN |
                 RCU_CTL_PLLSAIEN | RCU_CTL_HXTALBPS);
    /* reset PLL register */
    RCU_PLL = 0x24003010U;
    /* reset PLLI2S register */
    RCU_PLLI2S = 0x24003000U;
    /* reset PLLSAI register */
    RCU_PLLSAI = 0x24003010U;
    /* reset INT register */
    RCU_INT = 0x00000000U;
    /* reset CFG1 register */
    RCU_CFG1 &= ~(RCU_CFG1_PLLSAIRDIV | RCU_CFG1_TIMERSEL);                
}

/*!
    \brief      enable the peripherals clock
    \param[in]  periph: RCU peripherals, refer to rcu_periph_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_GPIOx (x=A,B,C,D,E,F,G,H,I): GPIO ports clock
      \arg        RCU_CRC: CRC clock
      \arg        RCU_BKPSRAM: BKPSRAM clock
      \arg        RCU_TCMSRAM: TCMSRAM clock
      \arg        RCU_DMAx (x=0,1): DMA clock
      \arg        RCU_IPA: IPA clock
      \arg        RCU_ENET: ENET clock
      \arg        RCU_ENETTX: ENETTX clock
      \arg        RCU_ENETRX: ENETRX clock
      \arg        RCU_ENETPTP: ENETPTP clock
      \arg        RCU_USBHS: USBHS clock
      \arg        RCU_USBHSULPI: USBHSULPI clock
      \arg        RCU_DCI: DCI clock
      \arg        RCU_TRNG: TRNG clock
      \arg        RCU_USBFS: USBFS clock
      \arg        RCU_EXMC: EXMC clock
      \arg        RCU_TIMERx (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13): TIMER clock
      \arg        RCU_WWDGT: WWDGT clock
      \arg        RCU_SPIx (x=0,1,2,3,4,5): SPI clock
      \arg        RCU_USARTx (x=0,1,2,5): USART clock
      \arg        RCU_UARTx (x=3,4,6,7): UART clock
      \arg        RCU_I2Cx (x=0,1,2): I2C clock
      \arg        RCU_CANx (x=0,1): CAN clock
      \arg        RCU_PMU: PMU clock
      \arg        RCU_DAC: DAC clock
      \arg        RCU_RTC: RTC clock
      \arg        RCU_ADCx (x=0,1,2): ADC clock
      \arg        RCU_SDIO: SDIO clock
      \arg        RCU_SYSCFG: SYSCFG clock
      \arg        RCU_TLI: TLI clock
      \arg        RCU_CTC: CTC clock
      \arg        RCU_IREF: IREF clock
    \param[out] none
    \retval     none
*/
void rcu_periph_clock_enable(rcu_periph_enum periph)
{
    RCU_REG_VAL(periph) |= BIT(RCU_BIT_POS(periph));
}

/*!
    \brief      disable the peripherals clock
    \param[in]  periph: RCU peripherals, refer to rcu_periph_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_GPIOx (x=A,B,C,D,E,F,G,H,I): GPIO ports clock
      \arg        RCU_CRC: CRC clock
      \arg        RCU_BKPSRAM: BKPSRAM clock
      \arg        RCU_TCMSRAM: TCMSRAM clock
      \arg        RCU_DMAx (x=0,1): DMA clock
      \arg        RCU_IPA: IPA clock
      \arg        RCU_ENET: ENET clock
      \arg        RCU_ENETTX: ENETTX clock
      \arg        RCU_ENETRX: ENETRX clock
      \arg        RCU_ENETPTP: ENETPTP clock
      \arg        RCU_USBHS: USBHS clock
      \arg        RCU_USBHSULPI: USBHSULPI clock
      \arg        RCU_DCI: DCI clock
      \arg        RCU_TRNG: TRNG clock
      \arg        RCU_USBFS: USBFS clock
      \arg        RCU_EXMC: EXMC clock
      \arg        RCU_TIMERx (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13): TIMER clock
      \arg        RCU_WWDGT: WWDGT clock
      \arg        RCU_SPIx (x=0,1,2,3,4,5): SPI clock
      \arg        RCU_USARTx (x=0,1,2,5): USART clock
      \arg        RCU_UARTx (x=3,4,6,7): UART clock
      \arg        RCU_I2Cx (x=0,1,2): I2C clock
      \arg        RCU_CANx (x=0,1): CAN clock
      \arg        RCU_PMU: PMU clock
      \arg        RCU_DAC: DAC clock
      \arg        RCU_RTC: RTC clock
      \arg        RCU_ADCx (x=0,1,2): ADC clock
      \arg        RCU_SDIO: SDIO clock
      \arg        RCU_SYSCFG: SYSCFG clock
      \arg        RCU_TLI: TLI clock
      \arg        RCU_CTC: CTC clock
      \arg        RCU_IREF: IREF clock
    \param[out] none
    \retval     none
*/
void rcu_periph_clock_disable(rcu_periph_enum periph)
{
    RCU_REG_VAL(periph) &= ~BIT(RCU_BIT_POS(periph));
}

/*!
    \brief      enable the peripherals clock when sleep mode
    \param[in]  periph: RCU peripherals, refer to rcu_periph_sleep_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_GPIOx_SLP (x=A,B,C,D,E,F,G,H,I): GPIO ports clock
      \arg        RCU_CRC_SLP: CRC clock
      \arg        RCU_FMC_SLP: FMC clock
      \arg        RCU_SRAM0_SLP: SRAM0 clock
      \arg        RCU_SRAM1_SLP: SRAM1 clock
      \arg        RCU_BKPSRAM: BKPSRAM clock
      \arg        RCU_SRAM2_SLP: SRAM2 clock
      \arg        RCU_DMAx_SLP (x=0,1): DMA clock
      \arg        RCU_IPA_SLP: IPA clock
      \arg        RCU_ENET_SLP: ENET clock
      \arg        RCU_ENETTX_SLP: ENETTX clock
      \arg        RCU_ENETRX_SLP: ENETRX clock
      \arg        RCU_ENETPTP_SLP: ENETPTP clock
      \arg        RCU_USBHS_SLP: USBHS clock
      \arg        RCU_USBHSULPI_SLP: USBHSULPI clock
      \arg        RCU_DCI_SLP: DCI clock
      \arg        RCU_TRNG_SLP: TRNG clock
      \arg        RCU_USBFS_SLP: USBFS clock
      \arg        RCU_EXMC_SLP: EXMC clock
      \arg        RCU_TIMERx_SLP (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13): TIMER clock
      \arg        RCU_WWDGT_SLP: WWDGT clock
      \arg        RCU_SPIx_SLP (x=0,1,2,3,4,5): SPI clock
      \arg        RCU_USARTx_SLP (x=0,1,2,5): USART clock
      \arg        RCU_UARTx_SLP (x=3,4,6,7): UART clock
      \arg        RCU_I2Cx_SLP (x=0,1,2): I2C clock
      \arg        RCU_CANx_SLP (x=0,1): CAN clock
      \arg        RCU_PMU_SLP: PMU clock
      \arg        RCU_DAC_SLP: DAC clock
      \arg        RCU_RTC_SLP: RTC clock
      \arg        RCU_ADCx_SLP (x=0,1,2): ADC clock
      \arg        RCU_SDIO_SLP: SDIO clock
      \arg        RCU_SYSCFG_SLP: SYSCFG clock
      \arg        RCU_TLI_SLP: TLI clock
      \arg        RCU_CTC_SLP: CTC clock
      \arg        RCU_IREF_SLP: IREF clock
    \param[out] none
    \retval     none
*/
void rcu_periph_clock_sleep_enable(rcu_periph_sleep_enum periph)
{
    RCU_REG_VAL(periph) |= BIT(RCU_BIT_POS(periph));
}

/*!
    \brief      disable the peripherals clock when sleep mode
    \param[in]  periph: RCU peripherals, refer to rcu_periph_sleep_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_GPIOx_SLP (x=A,B,C,D,E,F,G,H,I): GPIO ports clock
      \arg        RCU_CRC_SLP: CRC clock
      \arg        RCU_FMC_SLP: FMC clock
      \arg        RCU_SRAM0_SLP: SRAM0 clock
      \arg        RCU_SRAM1_SLP: SRAM1 clock
      \arg        RCU_BKPSRAM: BKPSRAM clock
      \arg        RCU_SRAM2_SLP: SRAM2 clock
      \arg        RCU_DMAx_SLP (x=0,1): DMA clock
      \arg        RCU_IPA_SLP: IPA clock
      \arg        RCU_ENET_SLP: ENET clock
      \arg        RCU_ENETTX_SLP: ENETTX clock
      \arg        RCU_ENETRX_SLP: ENETRX clock
      \arg        RCU_ENETPTP_SLP: ENETPTP clock
      \arg        RCU_USBHS_SLP: USBHS clock
      \arg        RCU_USBHSULPI_SLP: USBHSULPI clock
      \arg        RCU_DCI_SLP: DCI clock
      \arg        RCU_TRNG_SLP: TRNG clock
      \arg        RCU_USBFS_SLP: USBFS clock
      \arg        RCU_EXMC_SLP: EXMC clock
      \arg        RCU_TIMERx_SLP (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13): TIMER clock
      \arg        RCU_WWDGT_SLP: WWDGT clock
      \arg        RCU_SPIx_SLP (x=0,1,2,3,4,5): SPI clock
      \arg        RCU_USARTx_SLP (x=0,1,2,5): USART clock
      \arg        RCU_UARTx_SLP (x=3,4,6,7): UART clock
      \arg        RCU_I2Cx_SLP (x=0,1,2): I2C clock
      \arg        RCU_CANx_SLP (x=0,1): CAN clock
      \arg        RCU_PMU_SLP: PMU clock
      \arg        RCU_DAC_SLP: DAC clock
      \arg        RCU_RTC_SLP: RTC clock
      \arg        RCU_ADCx_SLP (x=0,1,2): ADC clock
      \arg        RCU_SDIO_SLP: SDIO clock
      \arg        RCU_SYSCFG_SLP: SYSCFG clock
      \arg        RCU_TLI_SLP: TLI clock
      \arg        RCU_CTC_SLP: CTC clock
      \arg        RCU_IREF_SLP: IREF clock
    \param[out] none
    \retval     none
*/
void rcu_periph_clock_sleep_disable(rcu_periph_sleep_enum periph)
{
    RCU_REG_VAL(periph) &= ~BIT(RCU_BIT_POS(periph));
}

/*!
    \brief      reset the peripherals
    \param[in]  periph_reset: RCU peripherals reset, refer to rcu_periph_reset_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_GPIOxRST (x=A,B,C,D,E,F,G,H,I): reset GPIO ports
      \arg        RCU_CRCRST: reset CRC
      \arg        RCU_DMAxRST (x=0,1): reset DMA
      \arg        RCU_IPAENRST: reset IPA
      \arg        RCU_ENETRST: reset ENET
      \arg        RCU_USBHSRST: reset USBHS
      \arg        RCU_DCIRST: reset DCI
      \arg        RCU_TRNGRST: reset TRNG
      \arg        RCU_USBFSRST: reset USBFS
      \arg        RCU_EXMCRST: reset EXMC
      \arg        RCU_TIMERxRST (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13): reset TIMER
      \arg        RCU_WWDGTRST: reset WWDGT
      \arg        RCU_SPIxRST (x=0,1,2,3,4,5): reset SPI
      \arg        RCU_USARTxRST (x=0,1,2,5): reset USART
      \arg        RCU_UARTxRST (x=3,4,6,7): reset UART
      \arg        RCU_I2CxRST (x=0,1,2): reset I2C
      \arg        RCU_CANxRST (x=0,1): reset CAN
      \arg        RCU_PMURST: reset PMU
      \arg        RCU_DACRST: reset DAC
      \arg        RCU_ADCRST (x=0,1,2): reset ADC
      \arg        RCU_SDIORST: reset SDIO
      \arg        RCU_SYSCFGRST: reset SYSCFG
      \arg        RCU_TLIRST: reset TLI
      \arg        RCU_CTCRST: reset CTC
      \arg        RCU_IREFRST: reset IREF
    \param[out] none
    \retval     none
*/
void rcu_periph_reset_enable(rcu_periph_reset_enum periph_reset)
{
    RCU_REG_VAL(periph_reset) |= BIT(RCU_BIT_POS(periph_reset));
}

/*!
    \brief      disable reset the peripheral
    \param[in]  periph_reset: RCU peripherals reset, refer to rcu_periph_reset_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_GPIOxRST (x=A,B,C,D,E,F,G,H,I): reset GPIO ports
      \arg        RCU_CRCRST: reset CRC
      \arg        RCU_DMAxRST (x=0,1): reset DMA
      \arg        RCU_IPAENRST: reset IPA
      \arg        RCU_ENETRST: reset ENET
      \arg        RCU_USBHSRST: reset USBHS
      \arg        RCU_DCIRST: reset DCI
      \arg        RCU_TRNGRST: reset TRNG
      \arg        RCU_USBFSRST: reset USBFS
      \arg        RCU_EXMCRST: reset EXMC
      \arg        RCU_TIMERxRST (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13): reset TIMER
      \arg        RCU_WWDGTRST: reset WWDGT
      \arg        RCU_SPIxRST (x=0,1,2,3,4,5): reset SPI
      \arg        RCU_USARTxRST (x=0,1,2,5): reset USART
      \arg        RCU_UARTxRST (x=3,4,6,7): reset UART
      \arg        RCU_I2CxRST (x=0,1,2): reset I2C
      \arg        RCU_CANxRST (x=0,1): reset CAN
      \arg        RCU_PMURST: reset PMU
      \arg        RCU_DACRST: reset DAC
      \arg        RCU_ADCRST (x=0,1,2): reset ADC
      \arg        RCU_SDIORST: reset SDIO
      \arg        RCU_SYSCFGRST: reset SYSCFG
      \arg        RCU_TLIRST: reset TLI
      \arg        RCU_CTCRST: reset CTC
      \arg        RCU_IREFRST: reset IREF
    \param[out] none
    \retval     none
*/
void rcu_periph_reset_disable(rcu_periph_reset_enum periph_reset)
{
    RCU_REG_VAL(periph_reset) &= ~BIT(RCU_BIT_POS(periph_reset));
}

/*!
    \brief      reset the BKP
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_bkp_reset_enable(void)
{
    RCU_BDCTL |= RCU_BDCTL_BKPRST;
}

/*!
    \brief      disable the BKP reset
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_bkp_reset_disable(void)
{
    RCU_BDCTL &= ~RCU_BDCTL_BKPRST;
}

/*!
    \brief      configure the system clock source
    \param[in]  ck_sys: system clock source select
                only one parameter can be selected which is shown as below:
      \arg        RCU_CKSYSSRC_IRC16M: select CK_IRC16M as the CK_SYS source
      \arg        RCU_CKSYSSRC_HXTAL: select CK_HXTAL as the CK_SYS source
      \arg        RCU_CKSYSSRC_PLLP: select CK_PLLP as the CK_SYS source
    \param[out] none
    \retval     none
*/
void rcu_system_clock_source_config(uint32_t ck_sys)
{
    uint32_t reg;
    
    reg = RCU_CFG0;
    /* reset the SCS bits and set according to ck_sys */
    reg &= ~RCU_CFG0_SCS;
    RCU_CFG0 = (reg | ck_sys);
}

/*!
    \brief      get the system clock source
    \param[in]  none
    \param[out] none
    \retval     which clock is selected as CK_SYS source
      \arg        RCU_SCSS_IRC16M: CK_IRC16M is selected as the CK_SYS source
      \arg        RCU_SCSS_HXTAL: CK_HXTAL is selected as the CK_SYS source
      \arg        RCU_SCSS_PLLP: CK_PLLP is selected as the CK_SYS source
*/
uint32_t rcu_system_clock_source_get(void)
{
    return (RCU_CFG0 & RCU_CFG0_SCSS);
}

/*!
    \brief      configure the AHB clock prescaler selection
    \param[in]  ck_ahb: AHB clock prescaler selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_AHB_CKSYS_DIVx, x=1, 2, 4, 8, 16, 64, 128, 256, 512
    \param[out] none
    \retval     none
*/
void rcu_ahb_clock_config(uint32_t ck_ahb)
{
    uint32_t reg;
    
    reg = RCU_CFG0;
    /* reset the AHBPS bits and set according to ck_ahb */
    reg &= ~RCU_CFG0_AHBPSC;
    RCU_CFG0 = (reg | ck_ahb);
}

/*!
    \brief      configure the APB1 clock prescaler selection
    \param[in]  ck_apb1: APB1 clock prescaler selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_APB1_CKAHB_DIV1: select CK_AHB as CK_APB1
      \arg        RCU_APB1_CKAHB_DIV2: select CK_AHB/2 as CK_APB1
      \arg        RCU_APB1_CKAHB_DIV4: select CK_AHB/4 as CK_APB1
      \arg        RCU_APB1_CKAHB_DIV8: select CK_AHB/8 as CK_APB1
      \arg        RCU_APB1_CKAHB_DIV16: select CK_AHB/16 as CK_APB1
    \param[out] none
    \retval     none
*/
void rcu_apb1_clock_config(uint32_t ck_apb1)
{
    uint32_t reg;
    
    reg = RCU_CFG0;
    /* reset the APB1PS and set according to ck_apb1 */
    reg &= ~RCU_CFG0_APB1PSC;
    RCU_CFG0 = (reg | ck_apb1);
}

/*!
    \brief      configure the APB2 clock prescaler selection
    \param[in]  ck_apb2: APB2 clock prescaler selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_APB2_CKAHB_DIV1: select CK_AHB as CK_APB2
      \arg        RCU_APB2_CKAHB_DIV2: select CK_AHB/2 as CK_APB2
      \arg        RCU_APB2_CKAHB_DIV4: select CK_AHB/4 as CK_APB2
      \arg        RCU_APB2_CKAHB_DIV8: select CK_AHB/8 as CK_APB2
      \arg        RCU_APB2_CKAHB_DIV16: select CK_AHB/16 as CK_APB2
    \param[out] none
    \retval     none
*/
void rcu_apb2_clock_config(uint32_t ck_apb2)
{
    uint32_t reg;
    
    reg = RCU_CFG0;
    /* reset the APB2PS and set according to ck_apb2 */
    reg &= ~RCU_CFG0_APB2PSC;
    RCU_CFG0 = (reg | ck_apb2);
}

/*!
    \brief      configure the CK_OUT0 clock source and divider
    \param[in]  ckout0_src: CK_OUT0 clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_CKOUT0SRC_IRC16M: IRC16M selected
      \arg        RCU_CKOUT0SRC_LXTAL: LXTAL selected
      \arg        RCU_CKOUT0SRC_HXTAL: HXTAL selected
      \arg        RCU_CKOUT0SRC_PLLP: PLLP selected
    \param[in]  ckout0_div: CK_OUT0 divider 
      \arg        RCU_CKOUT0_DIVx(x=1,2,3,4,5): CK_OUT0 is divided by x
    \param[out] none
    \retval     none
*/
void rcu_ckout0_config(uint32_t ckout0_src, uint32_t ckout0_div)
{
    uint32_t reg;
    
    reg = RCU_CFG0;
    /* reset the CKOUT0SRC, CKOUT0DIV and set according to ckout0_src and ckout0_div */
    reg &= ~(RCU_CFG0_CKOUT0SEL | RCU_CFG0_CKOUT0DIV );
    RCU_CFG0 = (reg | ckout0_src | ckout0_div);
}

/*!
    \brief      configure the CK_OUT1 clock source and divider
    \param[in]  ckout1_src: CK_OUT1 clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_CKOUT1SRC_SYSTEMCLOCK: system clock selected
      \arg        RCU_CKOUT1SRC_PLLI2SR: PLLI2SR selected
      \arg        RCU_CKOUT1SRC_HXTAL: HXTAL selected
      \arg        RCU_CKOUT1SRC_PLLP: PLLP selected           
    \param[in]  ckout1_div: CK_OUT1 divider 
      \arg        RCU_CKOUT1_DIVx(x=1,2,3,4,5): CK_OUT1 is divided by x
    \param[out] none
    \retval     none
*/
void rcu_ckout1_config(uint32_t ckout1_src, uint32_t ckout1_div)
{
    uint32_t reg;
    
    reg = RCU_CFG0;
    /* reset the CKOUT1SRC, CKOUT1DIV and set according to ckout1_src and ckout1_div */
    reg &= ~(RCU_CFG0_CKOUT1SEL | RCU_CFG0_CKOUT1DIV);
    RCU_CFG0 = (reg | ckout1_src | ckout1_div);
}

/*!
    \brief      configure the main PLL clock 
    \param[in]  pll_src: PLL clock source selection
      \arg        RCU_PLLSRC_IRC16M: select IRC16M as PLL source clock
      \arg        RCU_PLLSRC_HXTAL: select HXTAL as PLL source clock
    \param[in]  pll_psc: the PLL VCO source clock prescaler
      \arg         this parameter should be selected between 2 and 63
    \param[in]  pll_n: the PLL VCO clock multi factor
      \arg        this parameter should be selected between 64 and 500
    \param[in]  pll_p: the PLLP output frequency division factor from PLL VCO clock
      \arg        this parameter should be selected 2,4,6,8
    \param[in]  pll_q: the PLL Q output frequency division factor from PLL VCO clock
      \arg        this parameter should be selected between 2 and 15
    \param[out] none
    \retval     ErrStatus: SUCCESS or ERROR
*/
ErrStatus rcu_pll_config(uint32_t pll_src, uint32_t pll_psc, uint32_t pll_n, uint32_t pll_p, uint32_t pll_q)
{
    uint32_t ss_modulation_inc;
    uint32_t ss_modulation_reg;
    
    ss_modulation_inc = 0U;
    ss_modulation_reg = RCU_PLLSSCTL;

    /* calculate the minimum factor of PLLN */
    if((ss_modulation_reg & RCU_PLLSSCTL_SSCGON) == RCU_PLLSSCTL_SSCGON){
        if((ss_modulation_reg & RCU_SS_TYPE_DOWN) == RCU_SS_TYPE_DOWN){
            ss_modulation_inc += RCU_SS_MODULATION_DOWN_INC;
        }else{
            ss_modulation_inc += RCU_SS_MODULATION_CENTER_INC;
        }
    }
    
    /* check the function parameter */
    if(CHECK_PLL_PSC_VALID(pll_psc) && CHECK_PLL_N_VALID(pll_n,ss_modulation_inc) && 
       CHECK_PLL_P_VALID(pll_p) && CHECK_PLL_Q_VALID(pll_q)){
         RCU_PLL = pll_psc | (pll_n << 6) | (((pll_p >> 1) - 1U) << 16) |
                   (pll_src) | (pll_q << 24);
    }else{
        /* return status */
        return ERROR;
    }
    
    /* return status */
    return SUCCESS;
}

/*!
    \brief      configure the PLLI2S clock 
    \param[in]  plli2s_n: the PLLI2S VCO clock multi factor
      \arg        this parameter should be selected between 50 and 500
    \param[in]  plli2s_q: the PLLI2S Q output frequency division factor from PLLI2S VCO clock
      \arg        this parameter should be selected between 2 and 15
    \param[in]  plli2s_r: the PLLI2S R output frequency division factor from PLLI2S VCO clock
      \arg        this parameter should be selected between 2 and 7
    \param[out] none
    \retval     ErrStatus: SUCCESS or ERROR
*/
ErrStatus rcu_plli2s_config(uint32_t plli2s_n, uint32_t plli2s_q, uint32_t plli2s_r)
{
    /* check the function parameter */
    if(CHECK_PLLI2S_N_VALID(plli2s_n) && CHECK_PLLI2S_Q_VALID(plli2s_q) && CHECK_PLLI2S_R_VALID(plli2s_r)){
        RCU_PLLI2S = (plli2s_n << 6) | (plli2s_q << 24) | (plli2s_r << 28);
    }else{
        /* return status */
        return ERROR;
    }
    
    /* return status */
    return SUCCESS;  
}

/*!
    \brief      configure the PLLSAI clock 
    \param[in]  pllsai_n: the PLLSAI VCO clock multi factor
      \arg        this parameter should be selected between 50 and 500
    \param[in]  pllsai_p: the PLLSAI P output frequency division factor from PLL VCO clock
      \arg        this parameter should be selected 2,4,6,8
    \param[in]  pllsai_q: the PLLSAI Q output frequency division factor from PLL VCO clock
      \arg        this parameter should be selected between 2 and 15
    \param[in]  pllsai_r: the PLLSAI R output frequency division factor from PLL VCO clock
      \arg        this parameter should be selected between 2 and 7
    \param[out] none
    \retval     ErrStatus: SUCCESS or ERROR
*/
ErrStatus rcu_pllsai_config(uint32_t pllsai_n, uint32_t pllsai_p, uint32_t pllsai_q, uint32_t pllsai_r)
{
    /* check the function parameter */
    if(CHECK_PLLSAI_N_VALID(pllsai_n) && CHECK_PLLSAI_P_VALID(pllsai_p) && 
       CHECK_PLLSAI_Q_VALID(pllsai_q) && CHECK_PLLSAI_R_VALID(pllsai_r)){
        RCU_PLLSAI = (pllsai_n << 6U) | (((pllsai_p >> 1U) - 1U) << 16U) | (pllsai_q << 24U) | (pllsai_r << 28U);
    }else{
        /* return status */
        return ERROR;
    }
    
    /* return status */
    return SUCCESS;
}

/*!
    \brief      configure the RTC clock source selection
    \param[in]  rtc_clock_source: RTC clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_RTCSRC_NONE: no clock selected
      \arg        RCU_RTCSRC_LXTAL: CK_LXTAL selected as RTC source clock
      \arg        RCU_RTCSRC_IRC32K: CK_IRC32K selected as RTC source clock
      \arg        RCU_RTCSRC_HXTAL_DIV_RTCDIV: CK_HXTAL/RTCDIV selected as RTC source clock
    \param[out] none
    \retval     none
*/
void rcu_rtc_clock_config(uint32_t rtc_clock_source)
{
    uint32_t reg;
    
    reg = RCU_BDCTL; 
    /* reset the RTCSRC bits and set according to rtc_clock_source */
    reg &= ~RCU_BDCTL_RTCSRC;
    RCU_BDCTL = (reg | rtc_clock_source);
}

/*!
    \brief      configure the I2S clock source selection
    \param[in]  i2s_clock_source: I2S clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_I2SSRC_PLLI2S: CK_PLLI2S selected as I2S source clock
      \arg        RCU_I2SSRC_I2S_CKIN: external i2s_ckin pin selected as I2S source clock
    \param[out] none
    \retval     none
*/
void rcu_i2s_clock_config(uint32_t i2s_clock_source)
{
    uint32_t reg;
    
    reg = RCU_CFG0; 
    /* reset the I2SSEL bit and set according to i2s_clock_source */
    reg &= ~RCU_CFG0_I2SSEL;
    RCU_CFG0 = (reg | i2s_clock_source);
}

/*!
    \brief      configure the CK48M clock source selection
    \param[in]  ck48m_clock_source: CK48M clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_CK48MSRC_PLL48M: CK_PLL48M selected as CK48M source clock
      \arg        RCU_CK48MSRC_IRC48M: CK_IRC48M selected as CK48M source clock
    \param[out] none
    \retval     none
*/
void rcu_ck48m_clock_config(uint32_t ck48m_clock_source)
{
    uint32_t reg;
    
    reg = RCU_ADDCTL;
    /* reset the I2SSEL bit and set according to i2s_clock_source */
    reg &= ~RCU_ADDCTL_CK48MSEL;
    RCU_ADDCTL = (reg | ck48m_clock_source);
}

/*!
    \brief      configure the PLL48M clock source selection
    \param[in]  pll48m_clock_source: PLL48M clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_PLL48MSRC_PLLQ: CK_PLLQ selected as PLL48M source clock
      \arg        RCU_PLL48MSRC_PLLSAIP: CK_PLLSAIP selected as PLL48M source clock
    \param[out] none
    \retval     none
*/
void rcu_pll48m_clock_config(uint32_t pll48m_clock_source)
{
    uint32_t reg;
    
    reg = RCU_ADDCTL;
    /* reset the PLL48MSEL bit and set according to pll48m_clock_source */
    reg &= ~RCU_ADDCTL_PLL48MSEL;
    RCU_ADDCTL = (reg | pll48m_clock_source);
}

/*!
    \brief      configure the TIMER clock prescaler selection
    \param[in]  timer_clock_prescaler: TIMER clock selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_TIMER_PSC_MUL2: if APB1PSC/APB2PSC in RCU_CFG0 register is 0b0xx(CK_APBx = CK_AHB) 
                                      or 0b100(CK_APBx = CK_AHB/2), the TIMER clock is equal to CK_AHB(CK_TIMERx = CK_AHB).
                                      or else, the TIMER clock is twice the corresponding APB clock (TIMER in APB1 domain: CK_TIMERx = 2 x CK_APB1; 
                                      TIMER in APB2 domain: CK_TIMERx = 2 x CK_APB2)
      \arg        RCU_TIMER_PSC_MUL4: if APB1PSC/APB2PSC in RCU_CFG0 register is 0b0xx(CK_APBx = CK_AHB), 
                                      0b100(CK_APBx = CK_AHB/2), or 0b101(CK_APBx = CK_AHB/4), the TIMER clock is equal to CK_AHB(CK_TIMERx = CK_AHB). 
                                      or else, the TIMER clock is four timers the corresponding APB clock (TIMER in APB1 domain: CK_TIMERx = 4 x CK_APB1;  
                                      TIMER in APB2 domain: CK_TIMERx = 4 x CK_APB2)
    \param[out] none
    \retval     none
*/
void rcu_timer_clock_prescaler_config(uint32_t timer_clock_prescaler)
{
    /* configure the TIMERSEL bit and select the TIMER clock prescaler */
    if(timer_clock_prescaler == RCU_TIMER_PSC_MUL2){
        RCU_CFG1 &= timer_clock_prescaler;
    }else{
        RCU_CFG1 |= timer_clock_prescaler;
    }
}

/*!
    \brief      configure the PLLSAIR divider used as input of TLI
    \param[in]  pllsai_r_div: PLLSAIR divider used as input of TLI
                only one parameter can be selected which is shown as below:
      \arg        RCU_PLLSAIR_DIVx(x=2,4,8,16): PLLSAIR divided x used as input of TLI
    \param[out] none
    \retval     none
*/
void rcu_tli_clock_div_config(uint32_t pllsai_r_div)
{
    uint32_t reg;
    
    reg = RCU_CFG1;
    /* reset the PLLSAIRDIV bit and set according to pllsai_r_div */
    reg &= ~RCU_CFG1_PLLSAIRDIV;
    RCU_CFG1 = (reg | pllsai_r_div);
}

/*!
    \brief      get the clock stabilization and periphral reset flags
    \param[in]  flag: the clock stabilization and periphral reset flags, refer to rcu_flag_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_FLAG_IRC16MSTB: IRC16M stabilization flag
      \arg        RCU_FLAG_HXTALSTB: HXTAL stabilization flag
      \arg        RCU_FLAG_PLLSTB: PLL stabilization flag
      \arg        RCU_FLAG_PLLI2SSTB: PLLI2S stabilization flag
      \arg        RCU_FLAG_PLLSAISTB: PLLSAI stabilization flag
      \arg        RCU_FLAG_LXTALSTB: LXTAL stabilization flag
      \arg        RCU_FLAG_IRC32KSTB: IRC32K stabilization flag
      \arg        RCU_FLAG_IRC48MSTB: IRC48M stabilization flag
      \arg        RCU_FLAG_BORRST: BOR reset flags
      \arg        RCU_FLAG_EPRST: external PIN reset flag
      \arg        RCU_FLAG_PORRST: Power reset flag
      \arg        RCU_FLAG_SWRST: software reset flag
      \arg        RCU_FLAG_FWDGTRST: free watchdog timer reset flag
      \arg        RCU_FLAG_WWDGTRST: window watchdog timer reset flag
      \arg        RCU_FLAG_LPRST: low-power reset flag
    \param[out] none
    \retval     none
*/
FlagStatus rcu_flag_get(rcu_flag_enum flag)
{
    /* get the rcu flag */
    if(RESET != (RCU_REG_VAL(flag) & BIT(RCU_BIT_POS(flag)))){
        return SET;
    }else{
        return RESET;
    }
}

/*!
    \brief      clear all the reset flag
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_all_reset_flag_clear(void)
{
    RCU_RSTSCK |= RCU_RSTSCK_RSTFC;
}

/*!
    \brief      get the clock stabilization interrupt and ckm flags
    \param[in]  int_flag: interrupt and ckm flags, refer to rcu_int_flag_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_INT_FLAG_IRC32KSTB: IRC40K stabilization interrupt flag
      \arg        RCU_INT_FLAG_LXTALSTB: LXTAL stabilization interrupt flag
      \arg        RCU_INT_FLAG_IRC8MSTB: IRC8M stabilization interrupt flag
      \arg        RCU_INT_FLAG_HXTALSTB: HXTAL stabilization interrupt flag
      \arg        RCU_INT_FLAG_PLLSTB: PLL stabilization interrupt flag
      \arg        RCU_INT_FLAG_PLLI2SSTB: PLLI2S stabilization interrupt flag
      \arg        RCU_INT_FLAG_PLLSAISTB: PLLSAI stabilization interrupt flag
      \arg        RCU_INT_FLAG_CKM: HXTAL clock stuck interrupt flag
      \arg        RCU_INT_FLAG_IRC48MSTB: IRC48M stabilization interrupt flag
    \param[out] none
    \retval     FlagStatus: SET or RESET
*/
FlagStatus rcu_interrupt_flag_get(rcu_int_flag_enum int_flag)
{
    /* get the rcu interrupt flag */
    if(RESET != (RCU_REG_VAL(int_flag) & BIT(RCU_BIT_POS(int_flag)))){
        return SET;
    }else{
        return RESET;
    }
}

/*!
    \brief      clear the interrupt flags
    \param[in]  int_flag_clear: clock stabilization and stuck interrupt flags clear, refer to rcu_int_flag_clear_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_INT_FLAG_IRC32KSTB_CLR: IRC32K stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_LXTALSTB_CLR: LXTAL stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_IRC16MSTB_CLR: IRC16M stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_HXTALSTB_CLR: HXTAL stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_PLLSTB_CLR: PLL stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_PLLI2SSTB_CLR: PLLI2S stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_PLLSAISTB_CLR: PLLSAI stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_CKM_CLR: clock stuck interrupt flag clear
      \arg        RCU_INT_FLAG_IRC48MSTB_CLR: IRC48M stabilization interrupt flag clear
    \param[out] none
    \retval     none
*/
void rcu_interrupt_flag_clear(rcu_int_flag_clear_enum int_flag_clear)
{
    RCU_REG_VAL(int_flag_clear) |= BIT(RCU_BIT_POS(int_flag_clear));
}

/*!
    \brief      enable the stabilization interrupt
    \param[in]  stab_int: clock stabilization interrupt, refer to rcu_int_enum
                Only one parameter can be selected which is shown as below:
      \arg        RCU_INT_IRC32KSTB: IRC32K stabilization interrupt enable
      \arg        RCU_INT_LXTALSTB: LXTAL stabilization interrupt enable
      \arg        RCU_INT_IRC16MSTB: IRC16M stabilization interrupt enable
      \arg        RCU_INT_HXTALSTB: HXTAL stabilization interrupt enable
      \arg        RCU_INT_PLLSTB: PLL stabilization interrupt enable
      \arg        RCU_INT_PLLI2SSTB: PLLI2S stabilization interrupt enable
      \arg        RCU_INT_PLLSAISTB: PLLSAI stabilization interrupt enable
      \arg        RCU_INT_IRC48MSTB: IRC48M stabilization interrupt enable
    \param[out] none
    \retval     none
*/
void rcu_interrupt_enable(rcu_int_enum stab_int)
{
    RCU_REG_VAL(stab_int) |= BIT(RCU_BIT_POS(stab_int));
}


/*!
    \brief      disable the stabilization interrupt
    \param[in]  stab_int: clock stabilization interrupt, refer to rcu_int_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_INT_IRC32KSTB: IRC32K stabilization interrupt disable
      \arg        RCU_INT_LXTALSTB: LXTAL stabilization interrupt disable
      \arg        RCU_INT_IRC16MSTB: IRC16M stabilization interrupt disable
      \arg        RCU_INT_HXTALSTB: HXTAL stabilization interrupt disable
      \arg        RCU_INT_PLLSTB: PLL stabilization interrupt disable
      \arg        RCU_INT_PLLI2SSTB: PLLI2S stabilization interrupt disable
      \arg        RCU_INT_PLLSAISTB: PLLSAI stabilization interrupt disable
      \arg        RCU_INT_IRC48MSTB: IRC48M stabilization interrupt disable
    \param[out] none
    \retval     none
*/
void rcu_interrupt_disable(rcu_int_enum stab_int)
{
    RCU_REG_VAL(stab_int) &= ~BIT(RCU_BIT_POS(stab_int));
}

/*!
    \brief      configure the LXTAL drive capability
    \param[in]  lxtal_dricap: drive capability of LXTAL
                only one parameter can be selected which is shown as below:
      \arg        RCU_LXTALDRI_LOWER_DRIVE: lower driving capability
      \arg        RCU_LXTALDRI_HIGHER_DRIVE: higher driving capability
    \param[out] none
    \retval     none
*/
void rcu_lxtal_drive_capability_config(uint32_t lxtal_dricap)
{
    uint32_t reg;
    
    reg = RCU_BDCTL;
    
    /* reset the LXTALDRI bits and set according to lxtal_dricap */
    reg &= ~RCU_BDCTL_LXTALDRI;
    RCU_BDCTL = (reg | lxtal_dricap);
}

/*!
    \brief      wait for oscillator stabilization flags is SET or oscillator startup is timeout
    \param[in]  osci: oscillator types, refer to rcu_osci_type_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_HXTAL: HXTAL
      \arg        RCU_LXTAL: LXTAL
      \arg        RCU_IRC16M: IRC16M
      \arg        RCU_IRC48M: IRC48M
      \arg        RCU_IRC32K: IRC32K
      \arg        RCU_PLL_CK: PLL
      \arg        RCU_PLLI2S_CK: PLLI2S
      \arg        RCU_PLLSAI_CK: PLLSAI
    \param[out] none
    \retval     ErrStatus: SUCCESS or ERROR
*/
ErrStatus rcu_osci_stab_wait(rcu_osci_type_enum osci)
{
    uint32_t stb_cnt = 0U;
    ErrStatus reval = ERROR;
    FlagStatus osci_stat = RESET;
    
    switch(osci){
    /* wait HXTAL stable */
    case RCU_HXTAL:
        while((RESET == osci_stat) && (HXTAL_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_HXTALSTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if(RESET != rcu_flag_get(RCU_FLAG_HXTALSTB)){
            reval = SUCCESS;
        }
        break;
    /* wait LXTAL stable */
    case RCU_LXTAL:
        while((RESET == osci_stat) && (LXTAL_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_LXTALSTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if(RESET != rcu_flag_get(RCU_FLAG_LXTALSTB)){
            reval = SUCCESS;
        }
        break;
    /* wait IRC16M stable */    
    case RCU_IRC16M:
        while((RESET == osci_stat) && (IRC16M_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_IRC16MSTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if(RESET != rcu_flag_get(RCU_FLAG_IRC16MSTB)){
            reval = SUCCESS;
        }
        break;
    /* wait IRC48M stable */    
    case RCU_IRC48M:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_IRC48MSTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if (RESET != rcu_flag_get(RCU_FLAG_IRC48MSTB)){
            reval = SUCCESS;
        }
        break;
    /* wait IRC32K stable */
    case RCU_IRC32K:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_IRC32KSTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if(RESET != rcu_flag_get(RCU_FLAG_IRC32KSTB)){
            reval = SUCCESS;
        }
        break;
    /* wait PLL stable */    
    case RCU_PLL_CK:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_PLLSTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if(RESET != rcu_flag_get(RCU_FLAG_PLLSTB)){
            reval = SUCCESS;
        }
        break;
    /* wait PLLI2S stable */
    case RCU_PLLI2S_CK:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_PLLI2SSTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if(RESET != rcu_flag_get(RCU_FLAG_PLLI2SSTB)){
            reval = SUCCESS;
        }
        break;
    /* wait PLLSAI stable */    
    case RCU_PLLSAI_CK:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_PLLSAISTB);
            stb_cnt++;
        }
        
        /* check whether flag is set */
        if(RESET != rcu_flag_get(RCU_FLAG_PLLSAISTB)){
            reval = SUCCESS;
        }
        break;
    
    default:
        break;
    }
    
    /* return value */
    return reval;
}

/*!
    \brief      turn on the oscillator
    \param[in]  osci: oscillator types, refer to rcu_osci_type_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_HXTAL: HXTAL
      \arg        RCU_LXTAL: LXTAL
      \arg        RCU_IRC16M: IRC16M
      \arg        RCU_IRC48M: IRC48M
      \arg        RCU_IRC32K: IRC32K
      \arg        RCU_PLL_CK: PLL
      \arg        RCU_PLLI2S_CK: PLLI2S
      \arg        RCU_PLLSAI_CK: PLLSAI
    \param[out] none
    \retval     none
*/
void rcu_osci_on(rcu_osci_type_enum osci)
{
    RCU_REG_VAL(osci) |= BIT(RCU_BIT_POS(osci));
}

/*!
    \brief      turn off the oscillator
    \param[in]  osci: oscillator types, refer to rcu_osci_type_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_HXTAL: HXTAL
      \arg        RCU_LXTAL: LXTAL
      \arg        RCU_IRC16M: IRC16M
      \arg        RCU_IRC48M: IRC48M
      \arg        RCU_IRC32K: IRC32K
      \arg        RCU_PLL_CK: PLL
      \arg        RCU_PLLI2S_CK: PLLI2S
      \arg        RCU_PLLSAI_CK: PLLSAI
    \param[out] none
    \retval     none
*/
void rcu_osci_off(rcu_osci_type_enum osci)
{
    RCU_REG_VAL(osci) &= ~BIT(RCU_BIT_POS(osci));
}

/*!
    \brief      enable the oscillator bypass mode, HXTALEN or LXTALEN must be reset before it
    \param[in]  osci: oscillator types, refer to rcu_osci_type_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_HXTAL: HXTAL
      \arg        RCU_LXTAL: LXTAL
    \param[out] none
    \retval     none
*/
void rcu_osci_bypass_mode_enable(rcu_osci_type_enum osci)
{
    uint32_t reg;

    switch(osci){
    /* enable HXTAL to bypass mode */    
    case RCU_HXTAL:
        reg = RCU_CTL;
        RCU_CTL &= ~RCU_CTL_HXTALEN;
        RCU_CTL = (reg | RCU_CTL_HXTALBPS);
        break;
    /* enable LXTAL to bypass mode */
    case RCU_LXTAL:
        reg = RCU_BDCTL;
        RCU_BDCTL &= ~RCU_BDCTL_LXTALEN;
        RCU_BDCTL = (reg | RCU_BDCTL_LXTALBPS);
        break;
    case RCU_IRC16M:
    case RCU_IRC48M:
    case RCU_IRC32K:
    case RCU_PLL_CK:
    case RCU_PLLI2S_CK:
    case RCU_PLLSAI_CK:    
        break;
    default:
        break;
    }
}

/*!
    \brief      disable the oscillator bypass mode, HXTALEN or LXTALEN must be reset before it
    \param[in]  osci: oscillator types, refer to rcu_osci_type_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_HXTAL: HXTAL
      \arg        RCU_LXTAL: LXTAL
    \param[out] none
    \retval     none
*/
void rcu_osci_bypass_mode_disable(rcu_osci_type_enum osci)
{
    uint32_t reg;
    
    switch(osci){
    /* disable HXTAL to bypass mode */    
    case RCU_HXTAL:
        reg = RCU_CTL;
        RCU_CTL &= ~RCU_CTL_HXTALEN;
        RCU_CTL = (reg & ~RCU_CTL_HXTALBPS);
        break;
    /* disable LXTAL to bypass mode */
    case RCU_LXTAL:
        reg = RCU_BDCTL;
        RCU_BDCTL &= ~RCU_BDCTL_LXTALEN;
        RCU_BDCTL = (reg & ~RCU_BDCTL_LXTALBPS);
        break;
    case RCU_IRC16M:
    case RCU_IRC48M:
    case RCU_IRC32K:
    case RCU_PLL_CK:
    case RCU_PLLI2S_CK:
    case RCU_PLLSAI_CK:    
        break;
    default:
        break;
    }
}

/*!
    \brief      enable the HXTAL clock monitor
    \param[in]  none
    \param[out] none
    \retval     none
*/

void rcu_hxtal_clock_monitor_enable(void)
{
    RCU_CTL |= RCU_CTL_CKMEN;
}

/*!
    \brief      disable the HXTAL clock monitor
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_hxtal_clock_monitor_disable(void)
{
    RCU_CTL &= ~RCU_CTL_CKMEN;
}

/*!
    \brief      set the IRC16M adjust value
    \param[in]  irc16m_adjval: IRC16M adjust value, must be between 0 and 0x1F
    \param[out] none
    \retval     none
*/
void rcu_irc16m_adjust_value_set(uint32_t irc16m_adjval)
{
    uint32_t reg;
    
    reg = RCU_CTL;
    /* reset the IRC16MADJ bits and set according to irc16m_adjval */
    reg &= ~RCU_CTL_IRC16MADJ;
    RCU_CTL = (reg | ((irc16m_adjval & 0x1FU) << 3));
}

/*!
    \brief      unlock the voltage key
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_voltage_key_unlock(void)
{
    RCU_VKEY = RCU_VKEY_UNLOCK;
}

/*!
    \brief      deep-sleep mode voltage select
    \param[in]  dsvol: deep sleep mode voltage
                only one parameter can be selected which is shown as below:
      \arg        RCU_DEEPSLEEP_V_1_2: the core voltage is 1.2V
      \arg        RCU_DEEPSLEEP_V_1_1: the core voltage is 1.1V
      \arg        RCU_DEEPSLEEP_V_1_0: the core voltage is 1.0V
      \arg        RCU_DEEPSLEEP_V_0_9: the core voltage is 0.9V
    \param[out] none
    \retval     none
*/
void rcu_deepsleep_voltage_set(uint32_t dsvol)
{    
    dsvol &= RCU_DSV_DSLPVS;
    RCU_DSV = dsvol;
}

/*!
    \brief      configure the spread spectrum modulation for the main PLL clock
    \param[in]  spread_spectrum_type: PLL spread spectrum modulation type select
      \arg        RCU_SS_TYPE_CENTER: center spread type is selected
      \arg        RCU_SS_TYPE_DOWN: down spread type is selected
    \param[in]  modstep: configure PLL spread spectrum modulation profile amplitude and frequency
      \arg        This parameter should be selected between 0 and 7FFF.The following criteria must be met: MODSTEP*MODCNT=215-1
    \param[in]  modcnt: configure PLL spread spectrum modulation profile amplitude and frequency
      \arg        This parameter should be selected between 0 and 1FFF.The following criteria must be met: MODSTEP*MODCNT=215-1
    \param[out] none
    \retval     none
*/
void rcu_spread_spectrum_config(uint32_t spread_spectrum_type, uint32_t modstep, uint32_t modcnt)
{
    uint32_t reg;
    
    reg = RCU_PLLSSCTL;
    /* reset the RCU_PLLSSCTL register bits */
    reg &= ~(RCU_PLLSSCTL_MODCNT | RCU_PLLSSCTL_MODSTEP | RCU_PLLSSCTL_SS_TYPE);
    RCU_PLLSSCTL = (reg | spread_spectrum_type | modstep << 13 | modcnt);
}

/*!
    \brief      enable the PLL spread spectrum modulation
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_spread_spectrum_enable(void)
{
    RCU_PLLSSCTL |= RCU_PLLSSCTL_SSCGON;
}

/*!
    \brief      disable the PLL spread spectrum modulation
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_spread_spectrum_disable(void)
{
    RCU_PLLSSCTL &= ~RCU_PLLSSCTL_SSCGON;
}

/*!
    \brief      get the system clock, bus and peripheral clock frequency
    \param[in]  clock: the clock frequency which to get
                only one parameter can be selected which is shown as below:
      \arg        CK_SYS: system clock frequency
      \arg        CK_AHB: AHB clock frequency
      \arg        CK_APB1: APB1 clock frequency
      \arg        CK_APB2: APB2 clock frequency
    \param[out] none
    \retval     clock frequency of system, AHB, APB1, APB2
*/
uint32_t rcu_clock_freq_get(rcu_clock_freq_enum clock)
{
    uint32_t sws, ck_freq = 0U;
    uint32_t cksys_freq, ahb_freq, apb1_freq, apb2_freq;
    uint32_t pllpsc, plln, pllsel, pllp, ck_src, idx, clk_exp;
    
    /* exponent of AHB, APB1 and APB2 clock divider */
    const uint8_t ahb_exp[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
    const uint8_t apb1_exp[8] = {0, 0, 0, 0, 1, 2, 3, 4};
    const uint8_t apb2_exp[8] = {0, 0, 0, 0, 1, 2, 3, 4};

    sws = GET_BITS(RCU_CFG0, 2, 3);
    switch(sws){
    /* IRC16M is selected as CK_SYS */
    case SEL_IRC16M:
        cksys_freq = IRC16M_VALUE;
        break;
    /* HXTAL is selected as CK_SYS */
    case SEL_HXTAL:
        cksys_freq = HXTAL_VALUE;
        break;
    /* PLLP is selected as CK_SYS */
    case SEL_PLLP:
        /* get the value of PLLPSC[5:0] */
        pllpsc = GET_BITS(RCU_PLL, 0U, 5U);
        plln = GET_BITS(RCU_PLL, 6U, 14U);
        pllp = (GET_BITS(RCU_PLL, 16U, 17U) + 1U) * 2U;
        /* PLL clock source selection, HXTAL or IRC8M/2 */
        pllsel = (RCU_PLL & RCU_PLL_PLLSEL);
        if (RCU_PLLSRC_HXTAL == pllsel) {
            ck_src = HXTAL_VALUE;
        } else {
            ck_src = IRC16M_VALUE;
        }
        cksys_freq = ((ck_src / pllpsc) * plln)/pllp;
        break;
    /* IRC16M is selected as CK_SYS */
    default:
        cksys_freq = IRC16M_VALUE;
        break;
    }
    /* calculate AHB clock frequency */
    idx = GET_BITS(RCU_CFG0, 4, 7);
    clk_exp = ahb_exp[idx];
    ahb_freq = cksys_freq >> clk_exp;
    
    /* calculate APB1 clock frequency */
    idx = GET_BITS(RCU_CFG0, 10, 12);
    clk_exp = apb1_exp[idx];
    apb1_freq = ahb_freq >> clk_exp;
    
    /* calculate APB2 clock frequency */
    idx = GET_BITS(RCU_CFG0, 13, 15);
    clk_exp = apb2_exp[idx];
    apb2_freq = ahb_freq >> clk_exp;
    
    /* return the clocks frequency */
    switch(clock){
    case CK_SYS:
        ck_freq = cksys_freq;
        break;
    case CK_AHB:
        ck_freq = ahb_freq;
        break;
    case CK_APB1:
        ck_freq = apb1_freq;
        break;
    case CK_APB2:
        ck_freq = apb2_freq;
        break;
    default:
        break;
    }
    return ck_freq;
}