rt-thread/bsp/gd32303e-eval/Libraries/GD32F30x_standard_peripheral/Source/gd32f30x_rcu.c

/*!
    \file  gd32f30x_rcu.c
    \brief RCU driver
*/

/*
    Copyright (C) 2017 GigaDevice

    2017-02-10, V1.0.1, firmware for GD32F30x
*/

#include "gd32f30x_rcu.h"

/* define clock source */
#define SEL_IRC8M                   ((uint16_t)0U)
#define SEL_HXTAL                   ((uint16_t)1U)
#define SEL_PLL                     ((uint16_t)2U)

/* define startup timeout count */
#define OSC_STARTUP_TIMEOUT         ((uint32_t)0xFFFFFU)
#define LXTAL_STARTUP_TIMEOUT       ((uint32_t)0x3FFFFFFU)

/*!
    \brief      deinitialize the RCU
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_deinit(void)
{
    /* enable IRC8M */
    RCU_CTL |= RCU_CTL_IRC8MEN;
    rcu_osci_stab_wait(RCU_IRC8M);

    /* reset CFG0 register */
#if (defined(GD32F30X_HD) || defined(GD32F30X_XD))
    RCU_CFG0 &= ~(RCU_CFG0_SCS | RCU_CFG0_AHBPSC | RCU_CFG0_APB1PSC | RCU_CFG0_APB2PSC |
                  RCU_CFG0_ADCPSC | RCU_CFG0_PLLSEL | RCU_CFG0_PREDV0 | RCU_CFG0_PLLMF |
                  RCU_CFG0_USBDPSC | RCU_CFG0_CKOUT0SEL | RCU_CFG0_PLLMF_4 | RCU_CFG0_ADCPSC_2 | RCU_CFG0_PLLMF_5 | RCU_CFG0_USBDPSC_2);
#elif defined(GD32F30X_CL)
    RCU_CFG0 &= ~(RCU_CFG0_SCS | RCU_CFG0_AHBPSC | RCU_CFG0_APB1PSC | RCU_CFG0_APB2PSC |
                  RCU_CFG0_ADCPSC | RCU_CFG0_PLLSEL | RCU_CFG0_PREDV0_LSB | RCU_CFG0_PLLMF |
                  RCU_CFG0_USBFSPSC | RCU_CFG0_CKOUT0SEL | RCU_CFG0_ADCPSC_2 | RCU_CFG0_PLLMF_4 | RCU_CFG0_PLLMF_5 | RCU_CFG0_USBFSPSC_2);
#endif /* GD32F30X_HD and GD32F30X_XD */
    /* reset CTL register */
    RCU_CTL &= ~(RCU_CTL_HXTALEN | RCU_CTL_CKMEN | RCU_CTL_PLLEN);
    RCU_CTL &= ~RCU_CTL_HXTALBPS;
#ifdef GD32F30X_CL
    RCU_CTL &= ~(RCU_CTL_PLL1EN | RCU_CTL_PLL2EN);
#endif /* GD32F30X_CL */

    /* reset INT and CFG1 register */
#if (defined(GD32F30X_HD) || defined(GD32F30X_XD))
    RCU_INT = 0x009f0000U;
    RCU_CFG1 &= ~(RCU_CFG1_ADCPSC_3 | RCU_CFG1_PLLPRESEL);
#elif defined(GD32F30X_CL)
    RCU_INT = 0x00ff0000U;
    RCU_CFG1 &= ~(RCU_CFG1_PREDV0 | RCU_CFG1_PREDV1 | RCU_CFG1_PLL1MF | RCU_CFG1_PLL2MF |
                  RCU_CFG1_PREDV0SEL | RCU_CFG1_I2S1SEL | RCU_CFG1_I2S2SEL | RCU_CFG1_ADCPSC_3 |
                  RCU_CFG1_PLLPRESEL | RCU_CFG1_PLL2MF_4);
#endif /* GD32F30X_HD and GD32F30X_XD */
}

/*!
    \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): GPIO ports clock
      \arg        RCU_AF : alternate function clock
      \arg        RCU_CRC: CRC clock
      \arg        RCU_DMAx (x=0,1): DMA clock
      \arg        RCU_ENET: ENET clock(CL series available)
      \arg        RCU_ENETTX: ENETTX clock(CL series available)
      \arg        RCU_ENETRX: ENETRX clock(CL series available)
      \arg        RCU_USBD: USBD clock(HD,XD series available)
      \arg        RCU_USBFS: USBFS clock(CL series available)
      \arg        RCU_EXMC: EXMC clock
      \arg        RCU_TIMERx (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13,TIMER8..13 are not available for HD series): TIMER clock
      \arg        RCU_WWDGT: WWDGT clock
      \arg        RCU_SPIx (x=0,1,2): SPI clock
      \arg        RCU_USARTx (x=0,1,2): USART clock
      \arg        RCU_UARTx (x=3,4): UART clock
      \arg        RCU_I2Cx (x=0,1): I2C clock
      \arg        RCU_CANx (x=0,1,CAN1 is only available for CL series): CAN clock
      \arg        RCU_PMU: PMU clock
      \arg        RCU_DAC: DAC clock
      \arg        RCU_RTC: RTC clock
      \arg        RCU_ADCx (x=0,1,2,ADC2 is not available for CL series): ADC clock
      \arg        RCU_SDIO: SDIO clock(not available for CL series)
      \arg        RCU_CTC: CTC clock
      \arg        RCU_BKPI: BKP interface 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): GPIO ports clock
      \arg        RCU_AF: alternate function clock
      \arg        RCU_CRC: CRC clock
      \arg        RCU_DMAx (x=0,1): DMA clock
      \arg        RCU_ENET: ENET clock(CL series available)
      \arg        RCU_ENETTX: ENETTX clock(CL series available)
      \arg        RCU_ENETRX: ENETRX clock(CL series available)
      \arg        RCU_USBD: USBD clock(HD,XD series available)
      \arg        RCU_USBFS: USBFS clock(CL series available)
      \arg        RCU_EXMC: EXMC clock
      \arg        RCU_TIMERx (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13,TIMER8..13 are not available for HD series): TIMER clock
      \arg        RCU_WWDGT: WWDGT clock
      \arg        RCU_SPIx (x=0,1,2): SPI clock
      \arg        RCU_USARTx (x=0,1,2): USART clock
      \arg        RCU_UARTx (x=3,4): UART clock
      \arg        RCU_I2Cx (x=0,1): I2C clock
      \arg        RCU_CANx (x=0,1,CAN1 is only available for CL series): CAN clock
      \arg        RCU_PMU: PMU clock
      \arg        RCU_DAC: DAC clock
      \arg        RCU_RTC: RTC clock
      \arg        RCU_ADCx (x=0,1,2,ADC2 is not available for CL series): ADC clock
      \arg        RCU_SDIO: SDIO clock(not available for CL series)
      \arg        RCU_CTC: CTC clock
      \arg        RCU_BKPI: BKP interface 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_FMC_SLP: FMC clock
      \arg        RCU_SRAM_SLP: SRAM 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_FMC_SLP: FMC clock
      \arg        RCU_SRAM_SLP: SRAM 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): reset GPIO ports
      \arg        RCU_AFRST : reset alternate function clock
      \arg        RCU_ENETRST: reset ENET(CL series available)
      \arg        RCU_USBDRST: reset USBD(HD,XD series available)
      \arg        RCU_USBFSRST: reset USBFS(CL series available)
      \arg        RCU_TIMERxRST (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13,TIMER8..13 are not available for HD series): reset TIMER
      \arg        RCU_WWDGTRST: reset WWDGT
      \arg        RCU_SPIxRST (x=0,1,2): reset SPI
      \arg        RCU_USARTxRST (x=0,1,2): reset USART
      \arg        RCU_UARTxRST (x=3,4): reset UART
      \arg        RCU_I2CxRST (x=0,1): reset I2C
      \arg        RCU_CANxRST (x=0,1,CAN1 is only available for CL series): reset CAN
      \arg        RCU_PMURST: reset PMU
      \arg        RCU_DACRST: reset DAC
      \arg        RCU_ADCRST (x=0,1,2,ADC2 is not available for CL series): reset ADC
      \arg        RCU_CTCRST: reset CTC
      \arg        RCU_BKPIRST: reset BKPI
    \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): reset GPIO ports
      \arg        RCU_AFRST : reset alternate function clock
      \arg        RCU_ENETRST: reset ENET(CL series available)
      \arg        RCU_USBDRST: reset USBD(HD,XD series available)
      \arg        RCU_USBFSRST: reset USBFS(CL series available)
      \arg        RCU_TIMERxRST (x=0,1,2,3,4,5,6,7,8,9,10,11,12,13,TIMER8..13 are not available for HD series): reset TIMER
      \arg        RCU_WWDGTRST: reset WWDGT
      \arg        RCU_SPIxRST (x=0,1,2): reset SPI
      \arg        RCU_USARTxRST (x=0,1,2): reset USART
      \arg        RCU_UARTxRST (x=3,4): reset UART
      \arg        RCU_I2CxRST (x=0,1): reset I2C
      \arg        RCU_CANxRST (x=0,1,CAN1 is only available for CL series): reset CAN
      \arg        RCU_PMURST: reset PMU
      \arg        RCU_DACRST: reset DAC
      \arg        RCU_ADCRST (x=0,1,2,ADC2 is not available for CL series): reset ADC
      \arg        RCU_CTCRST: reset CTC
      \arg        RCU_BKPIRST: reset BKPI
    \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 domain
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_bkp_reset_enable(void)
{
    RCU_BDCTL |= RCU_BDCTL_BKPRST;
}

/*!
    \brief      disable the BKP domain 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_IRC8M: select CK_IRC8M as the CK_SYS source
      \arg        RCU_CKSYSSRC_HXTAL: select CK_HXTAL as the CK_SYS source
      \arg        RCU_CKSYSSRC_PLL: select CK_PLL 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_IRC8M: CK_IRC8M is selected as the CK_SYS source
      \arg        RCU_SCSS_HXTAL: CK_HXTAL is selected as the CK_SYS source
      \arg        RCU_SCSS_PLL: CK_PLL 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 AHBPSC 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 APB1PSC 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 APB2PSC and set according to ck_apb2 */
    reg &= ~RCU_CFG0_APB2PSC;
    RCU_CFG0 = (reg | ck_apb2);
}

/*!
    \brief      configure the CK_OUT0 clock source
    \param[in]  ckout0_src: CK_OUT0 clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_CKOUT0SRC_NONE: no clock selected
      \arg        RCU_CKOUT0SRC_CKSYS: system clock selected
      \arg        RCU_CKOUT0SRC_IRC8M: high speed 8M internal oscillator clock selected
      \arg        RCU_CKOUT0SRC_HXTAL: HXTAL selected
      \arg        RCU_CKOUT0SRC_CKPLL_DIV2: CK_PLL/2 selected
      \arg        RCU_CKOUT0SRC_CKPLL1: CK_PLL1 selected
      \arg        RCU_CKOUT0SRC_CKPLL2_DIV2: CK_PLL2/2 selected
      \arg        RCU_CKOUT0SRC_EXT1: EXT1 selected
      \arg        RCU_CKOUT0SRC_CKPLL2: PLL selected
    \param[out] none
    \retval     none
*/
void rcu_ckout0_config(uint32_t ckout0_src)
{
    uint32_t reg;
    
    reg = RCU_CFG0;

    /* reset the CKOUT0SRC, set according to ckout0_src */
    reg &= ~RCU_CFG0_CKOUT0SEL;
    RCU_CFG0 = (reg | ckout0_src);
}

/*!
    \brief      configure the main PLL clock 
    \param[in]  pll_src: PLL clock source selection
      \arg        RCU_PLLSRC_IRC8M_DIV2: IRC8M/2 clock selected as source clock of PLL
      \arg        RCU_PLLSRC_HXTAL_IRC48M: HXTAL or IRC48M selected as source clock of PLL
    \param[in]  pll_mul: PLL clock multiplication factor
      \arg        RCU_PLL_MULx (XD series x = 2..63, CL series x = 2..14, 16..63, 6.5)
    \param[out] none
    \retval     none
*/
void rcu_pll_config(uint32_t pll_src, uint32_t pll_mul)
{
    uint32_t reg = 0U;

    reg = RCU_CFG0;

    /* PLL clock source and multiplication factor configuration */
    reg &= ~(RCU_CFG0_PLLSEL | RCU_CFG0_PLLMF | RCU_CFG0_PLLMF_4 | RCU_CFG0_PLLMF_5);
    reg |= (pll_src | pll_mul);

    RCU_CFG0 = reg;
}

/*!
    \brief      configure the PLL clock source preselection
    \param[in]  pll_presel: PLL clock source preselection
      \arg        RCU_PLLPRESRC_HXTAL: HXTAL selected as PLL source clock
      \arg        RCU_PLLPRESRC_IRC48M: CK_PLL selected as PREDV0 input source clock
    \param[out] none
    \retval     none
*/
void rcu_pllpresel_config(uint32_t pll_presel)
{
    uint32_t reg = 0U;

    reg = RCU_CFG1;

    /* PLL clock source preselection */
    reg &= ~RCU_CFG1_PLLPRESEL;
    reg |= pll_presel;

    RCU_CFG1 = reg;
}

#if (defined(GD32F30X_HD) || defined(GD32F30X_XD))
/*!
    \brief      configure the PREDV0 division factor
    \param[in]  predv0_div: PREDV0 division factor
      \arg        RCU_PREDV0_DIVx, x = 1,2
    \param[out] none
    \retval     none
*/
void rcu_predv0_config(uint32_t predv0_div)
{
    uint32_t reg = 0U;

    reg = RCU_CFG0;
    /* reset PREDV0 bit */
    reg &= ~RCU_CFG0_PREDV0;
    if(RCU_PREDV0_DIV2 == predv0_div){
        /* set the PREDV0 bit */
        reg |= RCU_CFG0_PREDV0;
    }

    RCU_CFG0 = reg;
}
#elif defined(GD32F30X_CL)
/*!
    \brief      configure the PREDV0 division factor and clock source
    \param[in]  predv0_source: PREDV0 input clock source selection
      \arg        RCU_PREDV0SRC_HXTAL_IRC48M: HXTAL or IRC48M selected as PREDV0 input source clock
      \arg        RCU_PREDV0SRC_CKPLL1: CK_PLL1 selected as PREDV0 input source clock
    \param[in]  predv0_div: PREDV0 division factor
      \arg        RCU_PREDV0_DIVx, x = 1..16
    \param[out] none
    \retval     none
*/
void rcu_predv0_config(uint32_t predv0_source, uint32_t predv0_div)
{
    uint32_t reg = 0U;
    
    reg = RCU_CFG1;
    /* reset PREDV0SEL and PREDV0 bits */
    reg &= ~(RCU_CFG1_PREDV0SEL | RCU_CFG1_PREDV0);
    /* set the PREDV0SEL and PREDV0 division factor */
    reg |= (predv0_source | predv0_div);

    RCU_CFG1 = reg;
}

/*!
    \brief      configure the PREDV1 division factor
    \param[in]  predv1_div: PREDV1 division factor
      \arg        RCU_PREDV1_DIVx, x = 1..16
    \param[out] none
    \retval     none
*/
void rcu_predv1_config(uint32_t predv1_div)
{
    uint32_t reg = 0U;
    
    reg = RCU_CFG1;
    /* reset the PREDV1 bits */
    reg &= ~RCU_CFG1_PREDV1;
    /* set the PREDV1 division factor */
    reg |= predv1_div;

    RCU_CFG1 = reg;
}

/*!
    \brief      configure the PLL1 clock 
    \param[in]  pll_mul: PLL clock multiplication factor
      \arg        RCU_PLL1_MULx (x = 8..16, 20)
    \param[out] none
    \retval     none
*/
void rcu_pll1_config(uint32_t pll_mul)
{
    RCU_CFG1 &= ~RCU_CFG1_PLL1MF;
    RCU_CFG1 |= pll_mul;
}

/*!
    \brief      configure the PLL2 clock 
    \param[in]  pll_mul: PLL clock multiplication factor
      \arg        RCU_PLL2_MULx (x = 8..16, 18..32, 40)
    \param[out] none
    \retval     none
*/
void rcu_pll2_config(uint32_t pll_mul)
{
    RCU_CFG1 &= ~RCU_CFG1_PLL2MF;
    RCU_CFG1 |= pll_mul; 
}
#endif /* GD32F30X_HD and GD32F30X_XD */

/*!
    \brief      configure the ADC prescaler factor
    \param[in]  adc_psc: ADC prescaler factor
      \arg        RCU_CKADC_CKAPB2_DIV2: ADC prescaler select CK_APB2/2
      \arg        RCU_CKADC_CKAPB2_DIV4: ADC prescaler select CK_APB2/4
      \arg        RCU_CKADC_CKAPB2_DIV6: ADC prescaler select CK_APB2/6
      \arg        RCU_CKADC_CKAPB2_DIV8: ADC prescaler select CK_APB2/8
      \arg        RCU_CKADC_CKAPB2_DIV12: ADC prescaler select CK_APB2/12
      \arg        RCU_CKADC_CKAPB2_DIV16: ADC prescaler select CK_APB2/16
      \arg        RCU_CKADC_CKAHB_DIV5: ADC prescaler select CK_AHB/5
      \arg        RCU_CKADC_CKAHB_DIV6: ADC prescaler select CK_AHB/6
      \arg        RCU_CKADC_CKAHB_DIV10: ADC prescaler select CK_AHB/10
      \arg        RCU_CKADC_CKAHB_DIV20: ADC prescaler select CK_AHB/20
    \param[out] none
    \retval     none
*/
void rcu_adc_clock_config(uint32_t adc_psc)
{
    uint32_t reg0,reg1;

    /* reset the ADCPSC bits */
    reg0 = RCU_CFG0;
    reg0 &= ~(RCU_CFG0_ADCPSC_2 | RCU_CFG0_ADCPSC);
    reg1 = RCU_CFG1;
    reg1 &= ~RCU_CFG1_ADCPSC_3;

    /* set the ADC prescaler factor */
    switch(adc_psc){
        case RCU_CKADC_CKAPB2_DIV2:
        case RCU_CKADC_CKAPB2_DIV4:
        case RCU_CKADC_CKAPB2_DIV6:
        case RCU_CKADC_CKAPB2_DIV8:
            reg0 |= (adc_psc << 14);
            break;

        case RCU_CKADC_CKAPB2_DIV12:
        case RCU_CKADC_CKAPB2_DIV16:
            adc_psc &= ~BIT(2);
            reg0 |= (adc_psc << 14 | RCU_CFG0_ADCPSC_2);
            break;

        case RCU_CKADC_CKAHB_DIV5:
        case RCU_CKADC_CKAHB_DIV6:
        case RCU_CKADC_CKAHB_DIV10:
        case RCU_CKADC_CKAHB_DIV20:
            adc_psc &= ~BITS(2,3);
            reg0 |= (adc_psc << 14);
            reg1 |= RCU_CFG1_ADCPSC_3;
            break;
         
        default:
            break;
    }

    /* set the register */
    RCU_CFG0 = reg0;
    RCU_CFG1 = reg1;
}

/*!
    \brief      configure the USBD/USBFS prescaler factor
    \param[in]  adc_div: USB prescaler factor
      \arg        RCU_CKUSB_CKPLL_DIV1_5: USBD/USBFS prescaler select CK_PLL/1.5
      \arg        RCU_CKUSB_CKPLL_DIV1: USBD/USBFS prescaler select CK_PLL/1
      \arg        RCU_CKUSB_CKPLL_DIV2_5: USBD/USBFS prescaler select CK_PLL/2.5
      \arg        RCU_CKUSB_CKPLL_DIV2: USBD/USBFS prescaler select CK_PLL/2
      \arg        RCU_CKUSB_CKPLL_DIV3: USBD/USBFS prescaler select CK_PLL/3
      \arg        RCU_CKUSB_CKPLL_DIV3_5: USBD/USBFS prescaler select CK_PLL/3.5
      \arg        RCU_CKUSB_CKPLL_DIV4: USBD/USBFS prescaler select CK_PLL/4
    \param[out] none
    \retval     none
*/
void rcu_usb_clock_config(uint32_t usb_psc)
{
    uint32_t reg;
    
    reg = RCU_CFG0;

    /* configure the USBD/USBFS prescaler factor */
#if (defined(GD32F30X_HD) || defined(GD32F30X_XD))
    reg &= ~RCU_CFG0_USBDPSC;
#elif defined(GD32F30X_CL)
    reg &= ~RCU_CFG0_USBFSPSC;
#endif /* GD32F30X_HD and GD32F30X_XD */

    RCU_CFG0 = (reg | usb_psc);
}

/*!
    \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_IRC40K: CK_IRC40K selected as RTC source clock
      \arg        RCU_RTCSRC_HXTAL_DIV_128: CK_HXTAL/128 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);
}

#ifdef GD32F30X_CL
/*!
    \brief      configure the I2S1 clock source selection
    \param[in]  i2s_clock_source: I2S1 clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_I2S1SRC_CKSYS: System clock selected as I2S1 source clock
      \arg        RCU_I2S1SRC_CKPLL2_MUL2: CK_PLL2x2 selected as I2S1 source clock
    \param[out] none
    \retval     none
*/
void rcu_i2s1_clock_config(uint32_t i2s_clock_source)
{
    uint32_t reg;
    
    reg = RCU_CFG1; 
    /* reset the I2S1SEL bit and set according to i2s_clock_source */
    reg &= ~RCU_CFG1_I2S1SEL;
    RCU_CFG1 = (reg | i2s_clock_source);
}

/*!
    \brief      configure the I2S2 clock source selection
    \param[in]  i2s_clock_source: I2S2 clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_I2S2SRC_CKSYS: system clock selected as I2S2 source clock
      \arg        RCU_I2S2SRC_CKPLL2_MUL2: CK_PLL2x2 selected as I2S2 source clock
    \param[out] none
    \retval     none
*/
void rcu_i2s2_clock_config(uint32_t i2s_clock_source)
{
    uint32_t reg;
    
    reg = RCU_CFG1; 
    /* reset the I2S2SEL bit and set according to i2s_clock_source */
    reg &= ~RCU_CFG1_I2S2SEL;
    RCU_CFG1 = (reg | i2s_clock_source);
}
#endif /* GD32F30X_CL */

/*!
    \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_CKPLL: CK_PLL 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 CK48MSEL bit and set according to ck48m_clock_source */
    reg &= ~RCU_ADDCTL_CK48MSEL;
    RCU_ADDCTL = (reg | ck48m_clock_source);
}

/*!
    \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_IRC8MSTB: IRC8M stabilization flag
      \arg        RCU_FLAG_HXTALSTB: HXTAL stabilization flag
      \arg        RCU_FLAG_PLLSTB: PLL stabilization flag
      \arg        RCU_FLAG_PLL1STB: PLL1 stabilization flag(CL series only)
      \arg        RCU_FLAG_PLL2STB: PLL2 stabilization flag(CL series only)
      \arg        RCU_FLAG_LXTALSTB: LXTAL stabilization flag
      \arg        RCU_FLAG_IRC40KSTB: IRC40K stabilization flag
      \arg        RCU_FLAG_IRC48MSTB: IRC48M stabilization flag
      \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_IRC40KSTB: 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_PLL1STB: PLL1 stabilization interrupt flag(CL series only)
      \arg        RCU_INT_FLAG_PLL2STB: PLL2 stabilization interrupt flag(CL series only)
      \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_IRC40KSTB_CLR: IRC40K stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_LXTALSTB_CLR: LXTAL stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_IRC8MSTB_CLR: IRC8M 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_PLL1STB_CLR: PLL1 stabilization interrupt flag clear(CL series only)
      \arg        RCU_INT_FLAG_PLL2STB_CLR: PLL2 stabilization interrupt flag clear(CL series only)
      \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_IRC40KSTB: IRC40K stabilization interrupt enable
      \arg        RCU_INT_LXTALSTB: LXTAL stabilization interrupt enable
      \arg        RCU_INT_IRC8MSTB: IRC8M stabilization interrupt enable
      \arg        RCU_INT_HXTALSTB: HXTAL stabilization interrupt enable
      \arg        RCU_INT_PLLSTB: PLL stabilization interrupt enable
      \arg        RCU_INT_PLL1STB: PLL1 stabilization interrupt enable(CL series only)
      \arg        RCU_INT_PLL2STB: PLL2 stabilization interrupt enable(CL series only)
      \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_IRC40KSTB: IRC40K stabilization interrupt enable
      \arg        RCU_INT_LXTALSTB: LXTAL stabilization interrupt enable
      \arg        RCU_INT_IRC8MSTB: IRC8M stabilization interrupt enable
      \arg        RCU_INT_HXTALSTB: HXTAL stabilization interrupt enable
      \arg        RCU_INT_PLLSTB: PLL stabilization interrupt enable
      \arg        RCU_INT_PLL1STB: PLL1 stabilization interrupt enable(CL series only)
      \arg        RCU_INT_PLL2STB: PLL2 stabilization interrupt enable(CL series only)
      \arg        RCU_INT_IRC48MSTB: IRC48M stabilization interrupt enable
    \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_LXTAL_LOWDRI: lower driving capability
      \arg        RCU_LXTAL_MED_LOWDRI: medium low driving capability
      \arg        RCU_LXTAL_MED_HIGHDRI: medium high driving capability
      \arg        RCU_LXTAL_HIGHDRI: 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: high speed crystal oscillator(HXTAL)
      \arg        RCU_LXTAL: low speed crystal oscillator(LXTAL)
      \arg        RCU_IRC8M: internal 8M RC oscillators(IRC8M)
      \arg        RCU_IRC48M: internal 48M RC oscillators(IRC48M)
      \arg        RCU_IRC40K: internal 40K RC oscillator(IRC40K)
      \arg        RCU_PLL_CK: phase locked loop(PLL)
      \arg        RCU_PLL1_CK: phase locked loop 1(CL series only)
      \arg        RCU_PLL2_CK: phase locked loop 2(CL series only)
    \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 or not */
        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 or not */
        if(RESET != rcu_flag_get(RCU_FLAG_LXTALSTB)){
            reval = SUCCESS;
        }
        break;

    /* wait IRC8M stable */
    case RCU_IRC8M:
        while((RESET == osci_stat) && (IRC8M_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_IRC8MSTB);
            stb_cnt++;
        }

        /* check whether flag is set or not */
        if(RESET != rcu_flag_get(RCU_FLAG_IRC8MSTB)){
            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 or not */
        if (RESET != rcu_flag_get(RCU_FLAG_IRC48MSTB)){
            reval = SUCCESS;
        }
        break;

    /* wait IRC40K stable */
    case RCU_IRC40K:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_IRC40KSTB);
            stb_cnt++;
        }

        /* check whether flag is set or not */
        if(RESET != rcu_flag_get(RCU_FLAG_IRC40KSTB)){
            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 or not */
        if(RESET != rcu_flag_get(RCU_FLAG_PLLSTB)){
            reval = SUCCESS;
        }
        break;

#ifdef GD32F30X_CL
    /* wait PLL1 stable */
    case RCU_PLL1_CK:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_PLL1STB);
            stb_cnt++;
        }

        /* check whether flag is set or not */
        if(RESET != rcu_flag_get(RCU_FLAG_PLL1STB)){
            reval = SUCCESS;
        }
        break;
    /* wait PLL2 stable */
    case RCU_PLL2_CK:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_PLL2STB);
            stb_cnt++;
        }

        /* check whether flag is set or not */
        if(RESET != rcu_flag_get(RCU_FLAG_PLL2STB)){
            reval = SUCCESS;
        }
        break;
#endif /* GD32F30X_CL */

    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: high speed crystal oscillator(HXTAL)
      \arg        RCU_LXTAL: low speed crystal oscillator(LXTAL)
      \arg        RCU_IRC8M: internal 8M RC oscillators(IRC8M)
      \arg        RCU_IRC48M: internal 48M RC oscillators(IRC48M)
      \arg        RCU_IRC40K: internal 40K RC oscillator(IRC40K)
      \arg        RCU_PLL_CK: phase locked loop(PLL)
      \arg        RCU_PLL1_CK: phase locked loop 1(CL series only)
      \arg        RCU_PLL2_CK: phase locked loop 2(CL series only)
    \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: high speed crystal oscillator(HXTAL)
      \arg        RCU_LXTAL: low speed crystal oscillator(LXTAL)
      \arg        RCU_IRC8M: internal 8M RC oscillators(IRC8M)
      \arg        RCU_IRC48M: internal 48M RC oscillators(IRC48M)
      \arg        RCU_IRC40K: internal 40K RC oscillator(IRC40K)
      \arg        RCU_PLL_CK: phase locked loop(PLL)
      \arg        RCU_PLL1_CK: phase locked loop 1(CL series only)
      \arg        RCU_PLL2_CK: phase locked loop 2(CL series only)
    \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: high speed crystal oscillator(HXTAL)
      \arg        RCU_LXTAL: low speed crystal oscillator(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_IRC8M:
    case RCU_IRC48M:
    case RCU_IRC40K:
    case RCU_PLL_CK:
#ifdef GD32F30X_CL
    case RCU_PLL1_CK:
    case RCU_PLL2_CK:
#endif /* GD32F30X_CL */
        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: high speed crystal oscillator(HXTAL)
      \arg        RCU_LXTAL: low speed crystal oscillator(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_IRC8M:
    case RCU_IRC48M:
    case RCU_IRC40K:
    case RCU_PLL_CK:
#ifdef GD32F30X_CL
    case RCU_PLL1_CK:
    case RCU_PLL2_CK:
#endif /* GD32F30X_CL */
        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 IRC8M adjust value
    \param[in]  irc8m_adjval: IRC8M adjust value, must be between 0 and 0x1F
    \param[out] none
    \retval     none
*/
void rcu_irc8m_adjust_value_set(uint32_t irc8m_adjval)
{
    uint32_t reg;
    
    reg = RCU_CTL;
    /* reset the IRC8MADJ bits and set according to irc8m_adjval */
    reg &= ~RCU_CTL_IRC8MADJ;
    RCU_CTL = (reg | ((irc8m_adjval & 0x1FU) << 3));
}

/*!
    \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_0: the core voltage is 1.0V
      \arg        RCU_DEEPSLEEP_V_0_9: the core voltage is 0.9V
      \arg        RCU_DEEPSLEEP_V_0_8: the core voltage is 0.8V
      \arg        RCU_DEEPSLEEP_V_0_7: the core voltage is 0.7V
    \param[out] none
    \retval     none
*/
void rcu_deepsleep_voltage_set(uint32_t dsvol)
{    
    dsvol &= RCU_DSV_DSLPVS;
    RCU_DSV = dsvol;
}

/*!
    \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 pllsel, pllpresel, predv0sel, pllmf,ck_src, idx, clk_exp;
#ifdef GD32F30X_CL
    uint32_t predv0, predv1, pll1mf;
#endif /* GD32F30X_CL */

    /* exponent of AHB, APB1 and APB2 clock divider */
    uint8_t ahb_exp[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
    uint8_t apb1_exp[8] = {0, 0, 0, 0, 1, 2, 3, 4};
    uint8_t apb2_exp[8] = {0, 0, 0, 0, 1, 2, 3, 4};

    sws = GET_BITS(RCU_CFG0, 2, 3);
    switch(sws){
    /* IRC8M is selected as CK_SYS */
    case SEL_IRC8M:
        cksys_freq = IRC8M_VALUE;
        break;
    /* HXTAL is selected as CK_SYS */
    case SEL_HXTAL:
        cksys_freq = HXTAL_VALUE;
        break;
    /* PLL is selected as CK_SYS */
    case SEL_PLL:
        /* PLL clock source selection, HXTAL, IRC48M or IRC8M/2 */
        pllsel = (RCU_CFG0 & RCU_CFG0_PLLSEL);

        if(RCU_PLLSRC_HXTAL_IRC48M == pllsel) {
            /* PLL clock source is HXTAL or IRC48M */
            pllpresel = (RCU_CFG1 & RCU_CFG1_PLLPRESEL);
            
            if(RCU_PLLPRESRC_HXTAL == pllpresel){
                /* PLL clock source is HXTAL */
                ck_src = HXTAL_VALUE;
            }else{
                /* PLL clock source is IRC48 */
                ck_src = IRC48M_VALUE;
            }

#if (defined(GD32F30X_HD) || defined(GD32F30X_XD))
            predv0sel = (RCU_CFG0 & RCU_CFG0_PREDV0);
            /* PREDV0 input source clock divided by 2 */
            if(RCU_CFG0_PREDV0 == predv0sel){
                ck_src = HXTAL_VALUE/2U;
            }
#elif defined(GD32F30X_CL)
            predv0sel = (RCU_CFG1 & RCU_CFG1_PREDV0SEL);
            /* source clock use PLL1 */
            if(RCU_PREDV0SRC_CKPLL1 == predv0sel){
                predv1 = ((RCU_CFG1 & RCU_CFG1_PREDV1) >> 4) + 1U;
                pll1mf = (uint32_t)((RCU_CFG1 & RCU_CFG1_PLL1MF) >> 8) + 2U;
                if(17U == pll1mf){
                    pll1mf = 20U;
                }
                ck_src = (ck_src/predv1)*pll1mf;
            }
            predv0 = (RCU_CFG1 & RCU_CFG1_PREDV0) + 1U;
            ck_src /= predv0;
#endif /* GD32F30X_HD and GD32F30X_XD */
        }else{
            /* PLL clock source is IRC8M/2 */
            ck_src = IRC8M_VALUE/2U;
        }

        /* PLL multiplication factor */
        pllmf = GET_BITS(RCU_CFG0, 18, 21);
        if((RCU_CFG0 & RCU_CFG0_PLLMF_4)){
            pllmf |= 0x10U;
        }
        if((RCU_CFG0 & RCU_CFG0_PLLMF_5)){
            pllmf |= 0x20U;
        }
        if(pllmf < 15U){
            pllmf += 2U;
        }else if((pllmf >= 15U) && (pllmf <= 62U)){
            pllmf += 1U;
        }else{
            pllmf = 63U;
        }
        cksys_freq = ck_src*pllmf;
    #ifdef GD32F30X_CL
        if(15U == pllmf){
            cksys_freq = ck_src*6U + ck_src/2U;
        }
    #endif /* GD32F30X_CL */

        break;
    /* IRC8M is selected as CK_SYS */
    default:
        cksys_freq = IRC8M_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, 8, 10);
    clk_exp = apb1_exp[idx];
    apb1_freq = ahb_freq >> clk_exp;
    
    /* calculate APB2 clock frequency */
    idx = GET_BITS(RCU_CFG0, 11, 13);
    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;
}