standard_peripheral/source/gd32f3x0_rcu.c

/*!
    \file    gd32f3x0_rcu.c
    \brief   RCU driver

    \version 2017-06-06, V1.0.0, firmware for GD32F3x0
    \version 2019-06-01, V2.0.0, firmware for GD32F3x0
    \version 2020-09-30, V2.1.0, firmware for GD32F3x0
*/

/*
    Copyright (c) 2020, GigaDevice Semiconductor Inc.

    Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice, this
       list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright notice,
       this list of conditions and the following disclaimer in the documentation
       and/or other materials provided with the distribution.
    3. Neither the name of the copyright holder nor the names of its contributors
       may be used to endorse or promote products derived from this software without
       specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
OF SUCH DAMAGE.
*/

#include "gd32f3x0_rcu.h"

/* define clock source */
#define SEL_IRC8M                    ((uint32_t)0x00000000U)
#define SEL_HXTAL                    ((uint32_t)0x00000001U)
#define SEL_PLL                      ((uint32_t)0x00000002U)

/* define startup timeout count */
#define OSC_STARTUP_TIMEOUT          ((uint32_t)0x000FFFFFU)
#define LXTAL_STARTUP_TIMEOUT        ((uint32_t)0x03FFFFFFU)

/*!
    \brief      deinitialize the RCU
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_deinit(void)
{
    /* enable IRC8M */
    RCU_CTL0 |= RCU_CTL0_IRC8MEN;
    while(0U == (RCU_CTL0 & RCU_CTL0_IRC8MSTB)){
    }
    /* reset RCU */
    RCU_CFG0 &= ~(RCU_CFG0_SCS | RCU_CFG0_AHBPSC | RCU_CFG0_APB1PSC | RCU_CFG0_APB2PSC |\
                  RCU_CFG0_ADCPSC | RCU_CFG0_CKOUTSEL | RCU_CFG0_CKOUTDIV | RCU_CFG0_PLLDV);
    RCU_CFG0 &= ~(RCU_CFG0_PLLSEL | RCU_CFG0_PLLMF | RCU_CFG0_PLLMF4 | RCU_CFG0_PLLDV);
#if (defined(GD32F350))
    RCU_CFG0 &= ~(RCU_CFG0_USBFSPSC);
    RCU_CFG2 &= ~(RCU_CFG2_CECSEL | RCU_CFG2_USBFSPSC2);
#endif /* GD32F350 */
    RCU_CTL0 &= ~(RCU_CTL0_HXTALEN | RCU_CTL0_CKMEN | RCU_CTL0_PLLEN | RCU_CTL0_HXTALBPS);
    RCU_CFG1 &= ~(RCU_CFG1_PREDV | RCU_CFG1_PLLMF5 | RCU_CFG1_PLLPRESEL);
    RCU_CFG2 &= ~(RCU_CFG2_USART0SEL | RCU_CFG2_ADCSEL);
    RCU_CFG2 &= ~RCU_CFG2_IRC28MDIV;
    RCU_CFG2 &= ~RCU_CFG2_ADCPSC2;
    RCU_CTL1 &= ~RCU_CTL1_IRC28MEN;
    RCU_ADDCTL &= ~RCU_ADDCTL_IRC48MEN;
    RCU_INT = 0x00000000U;
    RCU_ADDINT = 0x00000000U;
}

/*!
    \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,F): GPIO ports clock
      \arg        RCU_DMA: DMA clock
      \arg        RCU_CRC: CRC clock
      \arg        RCU_TSI: TSI clock
      \arg        RCU_CFGCMP: CFGCMP clock
      \arg        RCU_ADC: ADC clock
      \arg        RCU_TIMERx (x=0,1,2,5,13,14,15,16): TIMER clock (RCU_TIMER5 only for GD32F350)
      \arg        RCU_SPIx (x=0,1): SPI clock
      \arg        RCU_USARTx (x=0,1): USART clock
      \arg        RCU_WWDGT: WWDGT clock
      \arg        RCU_I2Cx (x=0,1): I2C clock
      \arg        RCU_USBFS: USBFS clock (only for GD32F350)
      \arg        RCU_PMU: PMU clock
      \arg        RCU_DAC: DAC clock (only for GD32F350)
      \arg        RCU_CEC: CEC clock (only for GD32F350)
      \arg        RCU_CTC: CTC clock
      \arg        RCU_RTC: RTC 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,F): GPIO ports clock
      \arg        RCU_DMA: DMA clock
      \arg        RCU_CRC: CRC clock
      \arg        RCU_TSI: TSI clock
      \arg        RCU_CFGCMP: CFGCMP clock
      \arg        RCU_ADC: ADC clock
      \arg        RCU_TIMERx (x=0,1,2,5,13,14,15,16): TIMER clock (RCU_TIMER5 only for GD32F350)
      \arg        RCU_SPIx (x=0,1): SPI clock
      \arg        RCU_USARTx (x=0,1): USART clock
      \arg        RCU_WWDGT: WWDGT clock
      \arg        RCU_I2Cx (x=0,1): I2C clock
      \arg        RCU_USBFS: USBFS clock (only for GD32F350)
      \arg        RCU_PMU: PMU clock
      \arg        RCU_DAC: DAC clock (only for GD32F350)
      \arg        RCU_CEC: CEC clock (only for GD32F350)
      \arg        RCU_CTC: CTC clock
      \arg        RCU_RTC: RTC 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,F): reset GPIO ports
      \arg        RCU_TSIRST: reset TSI
      \arg        RCU_CFGCMPRST: reset CFGCMP
      \arg        RCU_ADCRST: reset ADC
      \arg        RCU_TIMERxRST (x=0,1,2,5,13,14,15,16): reset TIMER (RCU_TIMER5 only for GD32F350)
      \arg        RCU_SPIxRST (x=0,1): reset SPI
      \arg        RCU_USARTxRST (x=0,1): reset USART
      \arg        RCU_WWDGTRST: reset WWDGT
      \arg        RCU_I2CxRST (x=0,1): reset I2C
      \arg        RCU_USBFSRST: reset USBFS (only for GD32F350)
      \arg        RCU_PMURST: reset PMU
      \arg        RCU_DACRST: reset DAC (only for GD32F350)
      \arg        RCU_CECRST: reset CEC (only for GD32F350)
      \arg        RCU_CTCRST: reset CTC
    \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,F): reset GPIO ports
      \arg        RCU_TSIRST: reset TSI
      \arg        RCU_CFGCMPRST: reset CFGCMP
      \arg        RCU_ADCRST: reset ADC
      \arg        RCU_TIMERxRST (x=0,1,2,5,13,14,15,16): reset TIMER (RCU_TIMER5 only for GD32F350)
      \arg        RCU_SPIxRST (x=0,1,2): reset SPI
      \arg        RCU_USARTxRST (x=0,1): reset USART
      \arg        RCU_WWDGTRST: reset WWDGT
      \arg        RCU_I2CxRST (x=0,1,2): reset I2C
      \arg        RCU_USBFSRST: reset USBFS (only for GD32F350)
      \arg        RCU_PMURST: reset PMU
      \arg        RCU_DACRST: reset DAC (only for GD32F350)
      \arg        RCU_CECRST: reset CEC (only for GD32F350)
      \arg        RCU_CTCRST: reset CTC
    \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_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 cksys_source = 0U;
    cksys_source = RCU_CFG0;
    /* reset the SCS bits and set according to ck_sys */
    cksys_source &= ~RCU_CFG0_SCS;
    RCU_CFG0 = (ck_sys | cksys_source);
}

/*!
    \brief      get the system clock source
    \param[in]  none
    \param[out] none
    \retval     which clock is selected as CK_SYS source
                only one parameter can be selected which is shown as below:
      \arg        RCU_SCSS_IRC8M: select CK_IRC8M as the CK_SYS source
      \arg        RCU_SCSS_HXTAL: select CK_HXTAL as the CK_SYS source
      \arg        RCU_SCSS_PLL: select CK_PLL 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 ahbpsc = 0U;
    ahbpsc = RCU_CFG0;
    /* reset the AHBPSC bits and set according to ck_ahb */
    ahbpsc &= ~RCU_CFG0_AHBPSC;
    RCU_CFG0 = (ck_ahb | ahbpsc);
}

/*!
    \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 apb1psc = 0U;
    apb1psc = RCU_CFG0;
    /* reset the APB1PSC and set according to ck_apb1 */
    apb1psc &= ~RCU_CFG0_APB1PSC;
    RCU_CFG0 = (ck_apb1 | apb1psc);
}

/*!
    \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 apb2psc = 0U;
    apb2psc = RCU_CFG0;
    /* reset the APB2PSC and set according to ck_apb2 */
    apb2psc &= ~RCU_CFG0_APB2PSC;
    RCU_CFG0 = (ck_apb2 | apb2psc);
}

/*!
    \brief      configure the ADC clock prescaler selection
    \param[in]  ck_adc: ADC clock prescaler selection, refer to rcu_adc_clock_enum
                only one parameter can be selected which is shown as below:
      \arg        RCU_ADCCK_IRC28M_DIV2: select CK_IRC28M/2 as CK_ADC
      \arg        RCU_ADCCK_IRC28M: select CK_IRC28M as CK_ADC
      \arg        RCU_ADCCK_APB2_DIV2: select CK_APB2/2 as CK_ADC
      \arg        RCU_ADCCK_AHB_DIV3: select CK_AHB/3 as CK_ADC
      \arg        RCU_ADCCK_APB2_DIV4: select CK_APB2/4 as CK_ADC
      \arg        RCU_ADCCK_AHB_DIV5: select CK_AHB/5 as CK_ADC
      \arg        RCU_ADCCK_APB2_DIV6: select CK_APB2/6 as CK_ADC
      \arg        RCU_ADCCK_AHB_DIV7: select CK_AHB/7 as CK_ADC
      \arg        RCU_ADCCK_APB2_DIV8: select CK_APB2/8 as CK_ADC
      \arg        RCU_ADCCK_AHB_DIV9: select CK_AHB/9 as CK_ADC
    \param[out] none
    \retval     none
*/
void rcu_adc_clock_config(rcu_adc_clock_enum ck_adc)
{
    /* reset the ADCPSC, ADCSEL, IRC28MDIV bits */
    RCU_CFG0 &= ~RCU_CFG0_ADCPSC;
    RCU_CFG2 &= ~(RCU_CFG2_ADCSEL | RCU_CFG2_IRC28MDIV | RCU_CFG2_ADCPSC2);

    /* set the ADC clock according to ck_adc */
    switch(ck_adc){
    case RCU_ADCCK_IRC28M_DIV2:
        RCU_CFG2 &= ~RCU_CFG2_IRC28MDIV;
        RCU_CFG2 &= ~RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_IRC28M:
        RCU_CFG2 |= RCU_CFG2_IRC28MDIV;
        RCU_CFG2 &= ~RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_APB2_DIV2:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV2;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_AHB_DIV3:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV2;
        RCU_CFG2 |= RCU_CFG2_ADCPSC2;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_APB2_DIV4:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV4;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_AHB_DIV5:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV4;
        RCU_CFG2 |= RCU_CFG2_ADCPSC2;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_APB2_DIV6:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV6;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_AHB_DIV7:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV6;
        RCU_CFG2 |= RCU_CFG2_ADCPSC2;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_APB2_DIV8:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV8;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    case RCU_ADCCK_AHB_DIV9:
        RCU_CFG0 |= RCU_ADC_CKAPB2_DIV8;
        RCU_CFG2 |= RCU_CFG2_ADCPSC2;
        RCU_CFG2 |= RCU_CFG2_ADCSEL;
        break;
    default:
        break;
    }
}

/*!
    \brief      configure the USBFS clock prescaler selection
    \param[in]  ck_usbfs: USBFS clock prescaler selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_USBFS_CKPLL_DIV1_5: select CK_PLL/1.5 as CK_USBFS
      \arg        RCU_USBFS_CKPLL_DIV1: select CK_PLL as CK_USBFS
      \arg        RCU_USBFS_CKPLL_DIV2_5: select CK_PLL/2.5 as CK_USBFS
      \arg        RCU_USBFS_CKPLL_DIV2: select CK_PLL/2 as CK_USBFS
      \arg        RCU_USBFS_CKPLL_DIV3: select CK_PLL/3 as CK_USBFS
      \arg        RCU_USBFS_CKPLL_DIV3_5: select CK_PLL/3.5 as CK_USBFS
    \param[out] none
    \retval     none
*/
void rcu_usbfs_clock_config(uint32_t ck_usbfs)
{
    /* reset the USBFSPSC bits and set according to ck_usbfs */
    RCU_CFG0 &= ~RCU_CFG0_USBFSPSC;
    RCU_CFG2 &= ~RCU_CFG2_USBFSPSC2;

    RCU_CFG0 |= (ck_usbfs & (~RCU_CFG2_USBFSPSC2));
    RCU_CFG2 |= (ck_usbfs & RCU_CFG2_USBFSPSC2);
}

/*!
    \brief      configure the CK_OUT clock source and divider
    \param[in]  ckout_src: CK_OUT clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_CKOUTSRC_NONE: no clock selected
      \arg        RCU_CKOUTSRC_IRC28M: IRC28M selected
      \arg        RCU_CKOUTSRC_IRC40K: IRC40K selected
      \arg        RCU_CKOUTSRC_LXTAL: LXTAL selected
      \arg        RCU_CKOUTSRC_CKSYS: CKSYS selected
      \arg        RCU_CKOUTSRC_IRC8M: IRC8M selected
      \arg        RCU_CKOUTSRC_HXTAL: HXTAL selected
      \arg        RCU_CKOUTSRC_CKPLL_DIV1: CK_PLL selected
      \arg        RCU_CKOUTSRC_CKPLL_DIV2: CK_PLL/2 selected
    \param[in]  ckout_div: CK_OUT divider
      \arg        RCU_CKOUT_DIVx(x=1,2,4,8,16,32,64,128): CK_OUT is divided by x
    \param[out] none
    \retval     none
*/
void rcu_ckout_config(uint32_t ckout_src, uint32_t ckout_div)
{
    uint32_t ckout = 0U;
    ckout = RCU_CFG0;
    /* reset the CKOUTSEL, CKOUTDIV and PLLDV bits and set according to ckout_src and ckout_div */
    ckout &= ~(RCU_CFG0_CKOUTSEL | RCU_CFG0_CKOUTDIV | RCU_CFG0_PLLDV);
    RCU_CFG0 = (ckout | ckout_src | ckout_div);
}

/*!
    \brief      configure the PLL clock source preselection
    \param[in]  pll_presel: PLL clock source preselection
                only one parameter can be selected which is shown as below:
      \arg        RCU_PLLPRESEL_IRC48M: select IRC48M as PLL preselection clock
      \arg        RCU_PLLPRESEL_HXTAL: select HXTAL as PLL preselection clock
    \param[out] none
    \retval     none
*/
void rcu_pll_preselection_config(uint32_t pll_presel)
{
    RCU_CFG1 &= ~(RCU_CFG1_PLLPRESEL);
    RCU_CFG1 |= pll_presel;
}

/*!
    \brief      configure the PLL clock source selection and PLL multiply factor
    \param[in]  pll_src: PLL clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_PLLSRC_IRC8M_DIV2: select CK_IRC8M/2 as PLL source clock
      \arg        RCU_PLLSRC_HXTAL_IRC48M: select HXTAL or IRC48M as PLL source clock
    \param[in]  pll_mul: PLL multiply factor
                only one parameter can be selected which is shown as below:
      \arg        RCU_PLL_MULx(x=2..64): PLL source clock * x
    \param[out] none
    \retval     none
*/
void rcu_pll_config(uint32_t pll_src, uint32_t pll_mul)
{
    RCU_CFG0 &= ~(RCU_CFG0_PLLSEL | RCU_CFG0_PLLMF | RCU_CFG0_PLLMF4);
    RCU_CFG1 &= ~(RCU_CFG1_PLLMF5);
    RCU_CFG0 |= (pll_src | (pll_mul & (~RCU_CFG1_PLLMF5)));
    RCU_CFG1 |= (pll_mul & RCU_CFG1_PLLMF5);
}

/*!
    \brief      configure the USART clock source selection
    \param[in]  ck_usart: USART clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_USART0SRC_CKAPB2: CK_USART0 select CK_APB2
      \arg        RCU_USART0SRC_CKSYS: CK_USART0 select CK_SYS
      \arg        RCU_USART0SRC_LXTAL: CK_USART0 select CK_LXTAL
      \arg        RCU_USART0SRC_IRC8M: CK_USART0 select CK_IRC8M
    \param[out] none
    \retval     none
*/
void rcu_usart_clock_config(uint32_t ck_usart)
{
    /* reset the USART0SEL bits and set according to ck_usart */
    RCU_CFG2 &= ~RCU_CFG2_USART0SEL;
    RCU_CFG2 |= ck_usart;
}

/*!
    \brief      configure the CEC clock source selection
    \param[in]  ck_cec: CEC clock source selection
                only one parameter can be selected which is shown as below:
      \arg        RCU_CECSRC_IRC8M_DIV244: CK_CEC select CK_IRC8M/244
      \arg        RCU_CECSRC_LXTAL: CK_CEC select CK_LXTAL
    \param[out] none
    \retval     none
*/
void rcu_cec_clock_config(uint32_t ck_cec)
{
    /* reset the CECSEL bit and set according to ck_cec */
    RCU_CFG2 &= ~RCU_CFG2_CECSEL;
    RCU_CFG2 |= ck_cec;
}

/*!
    \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_DIV32: CK_HXTAL/32 selected as RTC source clock
    \param[out] none
    \retval     none
*/
void rcu_rtc_clock_config(uint32_t rtc_clock_source)
{
    /* reset the RTCSRC bits and set according to rtc_clock_source */
    RCU_BDCTL &= ~RCU_BDCTL_RTCSRC;
    RCU_BDCTL |= rtc_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 CK48MSEL bit and set according to ck48m_clock_source */
    reg &= ~RCU_ADDCTL_CK48MSEL;
    RCU_ADDCTL = (reg | ck48m_clock_source);
}

/*!
    \brief      configure the HXTAL divider used as input of PLL
    \param[in]  hxtal_prediv: HXTAL divider used as input of PLL
                only one parameter can be selected which is shown as below:
      \arg        RCU_PLL_PREDVx(x=1..16): HXTAL or IRC48M divided x used as input of PLL
    \param[out] none
    \retval     none
*/
void rcu_hxtal_prediv_config(uint32_t hxtal_prediv)
{
    uint32_t prediv = 0U;
    prediv = RCU_CFG1;
    /* reset the HXTALPREDV bits and set according to hxtal_prediv */
    prediv &= ~RCU_CFG1_PREDV;
    RCU_CFG1 = (prediv | hxtal_prediv);
}

/*!
    \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)
{
    /* reset the LXTALDRI bits and set according to lxtal_dricap */
    RCU_BDCTL &= ~RCU_BDCTL_LXTALDRI;
    RCU_BDCTL |= lxtal_dricap;
}

/*!
    \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_IRC40KSTB: IRC40K stabilization flag
      \arg        RCU_FLAG_LXTALSTB: LXTAL stabilization flag
      \arg        RCU_FLAG_IRC8MSTB: IRC8M stabilization flag
      \arg        RCU_FLAG_HXTALSTB: HXTAL stabilization flag
      \arg        RCU_FLAG_PLLSTB: PLL stabilization flag
      \arg        RCU_FLAG_IRC28MSTB: IRC28M stabilization flag
      \arg        RCU_FLAG_IRC48MSTB: IRC48M stabilization flag
      \arg        RCU_FLAG_V12RST: V12 domain power reset flag
      \arg        RCU_FLAG_OBLRST: option byte loader reset 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     FlagStatus: SET or RESET
*/
FlagStatus rcu_flag_get(rcu_flag_enum flag)
{
    if(RESET != (RCU_REG_VAL(flag) & BIT(RCU_BIT_POS(flag)))){
        return SET;
    }else{
        return RESET;
    }
}

/*!
    \brief      clear 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_IRC28MSTB: IRC28M stabilization interrupt flag
      \arg        RCU_INT_FLAG_IRC48MSTB: IRC48M stabilization interrupt flag
      \arg        RCU_INT_FLAG_CKM: HXTAL clock stuck interrupt flag
    \param[out] none
    \retval     FlagStatus: SET or RESET
*/
FlagStatus rcu_interrupt_flag_get(rcu_int_flag_enum int_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_IRC28MSTB_CLR: IRC28M stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_IRC48MSTB_CLR: IRC48M stabilization interrupt flag clear
      \arg        RCU_INT_FLAG_CKM_CLR: clock stuck 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_IRC28MSTB: IRC28M 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_IRC40KSTB: IRC40K stabilization interrupt disable
      \arg        RCU_INT_LXTALSTB: LXTAL stabilization interrupt disable
      \arg        RCU_INT_IRC8MSTB: IRC8M stabilization interrupt disable
      \arg        RCU_INT_HXTALSTB: HXTAL stabilization interrupt disable
      \arg        RCU_INT_PLLSTB: PLL stabilization interrupt disable
      \arg        RCU_INT_IRC28MSTB: IRC28M 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      wait until oscillator stabilization flags is SET
    \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_IRC8M: IRC8M
      \arg        RCU_IRC28M: IRC28M
      \arg        RCU_IRC48M: IRC48M
      \arg        RCU_IRC40K: IRC40K
      \arg        RCU_PLL_CK: PLL
    \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){
    case RCU_HXTAL:
         /* wait until HXTAL is stabilization and osci_stat is not more than timeout */
        while((RESET == osci_stat) && (HXTAL_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_HXTALSTB);
            stb_cnt++;
        }
        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 IRC28M stable */
    case RCU_IRC28M:
        while((RESET == osci_stat) && (OSC_STARTUP_TIMEOUT != stb_cnt)){
            osci_stat = rcu_flag_get(RCU_FLAG_IRC28MSTB);
            stb_cnt++;
        }

        /* check whether flag is set or not */
        if(RESET != rcu_flag_get(RCU_FLAG_IRC28MSTB)){
            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;

    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_IRC8M: IRC8M
      \arg        RCU_IRC28M: IRC28M
      \arg        RCU_IRC48M: IRC48M
      \arg        RCU_IRC40K: IRC40K
      \arg        RCU_PLL_CK: PLL
    \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_IRC8M: IRC8M
      \arg        RCU_IRC28M: IRC28M
      \arg        RCU_IRC48M: IRC48M
      \arg        RCU_IRC40K: IRC40K
      \arg        RCU_PLL_CK: PLL
    \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){
    case RCU_HXTAL:
        /* HXTALEN must be reset before enable the oscillator bypass mode */
        reg = RCU_CTL0;
        RCU_CTL0 &= ~RCU_CTL0_HXTALEN;
        RCU_CTL0 = (reg | RCU_CTL0_HXTALBPS);
        break;
    case RCU_LXTAL:
        /* LXTALEN must be reset before enable the oscillator bypass mode */
        reg = RCU_BDCTL;
        RCU_BDCTL &= ~RCU_BDCTL_LXTALEN;
        RCU_BDCTL = (reg | RCU_BDCTL_LXTALBPS);
        break;
    case RCU_IRC8M:
    case RCU_IRC28M:
    case RCU_IRC48M:
    case RCU_IRC40K:
    case RCU_PLL_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){
    case RCU_HXTAL:
        /* HXTALEN must be reset before disable the oscillator bypass mode */
        reg = RCU_CTL0;
        RCU_CTL0 &= ~RCU_CTL0_HXTALEN;
        RCU_CTL0 = (reg & (~RCU_CTL0_HXTALBPS));
        break;
    case RCU_LXTAL:
        /* LXTALEN must be reset before disable the oscillator bypass mode */
        reg = RCU_BDCTL;
        RCU_BDCTL &= ~RCU_BDCTL_LXTALEN;
        RCU_BDCTL = (reg & (~RCU_BDCTL_LXTALBPS));
        break;
    case RCU_IRC8M:
    case RCU_IRC28M:
    case RCU_IRC48M:
    case RCU_IRC40K:
    case RCU_PLL_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_CTL0 |= RCU_CTL0_CKMEN;
}

/*!
    \brief      disable the HXTAL clock monitor
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_hxtal_clock_monitor_disable(void)
{
    RCU_CTL0 &= ~RCU_CTL0_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(uint8_t irc8m_adjval)
{
    uint32_t adjust = 0U;
    adjust = RCU_CTL0;
    /* reset the IRC8MADJ bits and set according to irc8m_adjval */
    adjust &= ~RCU_CTL0_IRC8MADJ;
    RCU_CTL0 = (adjust | (((uint32_t)irc8m_adjval)<<3));
}

/*!
    \brief      set the IRC28M adjust value
    \param[in]  irc28m_adjval: IRC28M adjust value, must be between 0 and 0x1F
    \param[out] none
    \retval     none
*/
void rcu_irc28m_adjust_value_set(uint8_t irc28m_adjval)
{
    uint32_t adjust = 0U;
    adjust = RCU_CTL1;
    /* reset the IRC28MADJ bits and set according to irc28m_adjval */
    adjust &= ~RCU_CTL1_IRC28MADJ;
    RCU_CTL1 = (adjust | (((uint32_t)irc28m_adjval)<<3));
}

/*!
    \brief      unlock the voltage key
    \param[in]  none
    \param[out] none
    \retval     none
*/
void rcu_voltage_key_unlock(void)
{
    /* reset the KEY bits and set 0x1A2B3C4D */
    RCU_VKEY &= ~RCU_VKEY_KEY;
    RCU_VKEY |= RCU_VKEY_UNLOCK;
}

/*!
    \brief      set voltage in deep sleep mode
    \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(customers are not recommended to use it)
      \arg        RCU_DEEPSLEEP_V_0_8: the core voltage is 0.8V(customers are not recommended to use it)
      \arg        RCU_DEEPSLEEP_V_0_7: the core voltage is 0.7V(customers are not recommended to use it)
    \param[out] none
    \retval     none
*/
void rcu_deepsleep_voltage_set(uint32_t dsvol)
{
    /* reset the DSLPVS bits and set according to dsvol */
    RCU_DSV &= ~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
      \arg        CK_ADC: ADC clock frequency
      \arg        CK_CEC: CEC clock frequency
      \arg        CK_USART: USART clock frequency
    \param[out] none
    \retval     clock frequency of system, AHB, APB1, APB2, ADC, CEC or USRAT
*/
uint32_t rcu_clock_freq_get(rcu_clock_freq_enum clock)
{
    uint32_t sws = 0U, adcps = 0U, adcps2 = 0U, ck_freq = 0U;
    uint32_t cksys_freq = 0U, ahb_freq = 0U, apb1_freq = 0U, apb2_freq = 0U;
    uint32_t adc_freq = 0U, cec_freq = 0U, usart_freq = 0U;
    uint32_t pllmf = 0U, pllmf4 = 0U, pllmf5 = 0U, pllsel = 0U, pllpresel = 0U, prediv = 0U, idx = 0U, clk_exp = 0U;
    /* 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){
    /* 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:
        /* get the value of PLLMF[3:0] */
        pllmf = GET_BITS(RCU_CFG0, 18, 21);
        pllmf4 = GET_BITS(RCU_CFG0, 27, 27);
        pllmf5 = GET_BITS(RCU_CFG1, 31, 31);
        /* high 16 bits */
        /* high 16 bits */
        if((0U == pllmf4)&&(0U == pllmf5)){
            pllmf += 2U;
        }
        if((1U == pllmf4)&&(0U == pllmf5)){
            pllmf += 17U;
        }
        if((0U == pllmf4)&&(1U == pllmf5)){
            pllmf += 33U;
        }
        if((1U == pllmf4)&&(1U == pllmf5)){
            pllmf += 49U;
        }

        /* PLL clock source selection, HXTAL or IRC48M or IRC8M/2 */
        pllsel = GET_BITS(RCU_CFG0, 16, 16);
        pllpresel = GET_BITS(RCU_CFG1, 30, 30);
        if(0U != pllsel){
            prediv = (GET_BITS(RCU_CFG1,0, 3) + 1U);
            if(0U == pllpresel){
                cksys_freq = (HXTAL_VALUE / prediv) * pllmf;
            }else{
                cksys_freq = (IRC48M_VALUE / prediv) * pllmf;
            }
        }else{
            cksys_freq = (IRC8M_VALUE >> 1) * pllmf;
        }
        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;
    case CK_ADC:
        /* calculate ADC clock frequency */
        if(RCU_ADCSRC_AHB_APB2DIV != (RCU_CFG2 & RCU_CFG2_ADCSEL)){
            if(RCU_ADC_IRC28M_DIV1 != (RCU_CFG2 & RCU_CFG2_IRC28MDIV)){
                adc_freq = IRC28M_VALUE >> 1;
            }else{
                adc_freq = IRC28M_VALUE;
            }
        }else{
            /* ADC clock select CK_APB2 divided by 2/4/6/8 or CK_AHB divided by 3/5/7/9 */
            adcps = GET_BITS(RCU_CFG0, 14, 15);
            adcps2 = GET_BITS(RCU_CFG2, 31, 31);
            switch(adcps){
            case 0:
                if(0U == adcps2){
                   adc_freq = apb2_freq / 2U;
                }else{
                   adc_freq = ahb_freq / 3U;
                }
                break;
            case 1:
                if(0U == adcps2){
                   adc_freq = apb2_freq / 4U;
                }else{
                   adc_freq = ahb_freq / 5U;
                }
                break;
            case 2:
                if(0U == adcps2){
                   adc_freq = apb2_freq / 6U;
                }else{
                   adc_freq = ahb_freq / 7U;
                }
                break;
            case 3:
                if(0U == adcps2){
                   adc_freq = apb2_freq / 8U;
                }else{
                   adc_freq = ahb_freq / 9U;
                }
                break;
            default:
                break;
            }
        }
        ck_freq = adc_freq;
        break;
    case CK_CEC:
        /* calculate CEC clock frequency */
        if(RCU_CECSRC_LXTAL != (RCU_CFG2 & RCU_CFG2_CECSEL)){
            cec_freq = IRC8M_VALUE / 244U;
        }else{
            cec_freq = LXTAL_VALUE;
        }
        ck_freq = cec_freq;
        break;
    case CK_USART:
        /* calculate USART clock frequency */
        if(RCU_USART0SRC_CKAPB2 == (RCU_CFG2 & RCU_CFG2_USART0SEL)){
            usart_freq = apb2_freq;
        }else if(RCU_USART0SRC_CKSYS == (RCU_CFG2 & RCU_CFG2_USART0SEL)){
            usart_freq = cksys_freq;
        }else if(RCU_USART0SRC_LXTAL == (RCU_CFG2 & RCU_CFG2_USART0SEL)){
            usart_freq = LXTAL_VALUE;
        }else if(RCU_USART0SRC_IRC8M == (RCU_CFG2 & RCU_CFG2_USART0SEL)){
            usart_freq = IRC8M_VALUE;
        }else{
        }
        ck_freq = usart_freq;
        break;
    default:
        break;
    }
    return ck_freq;
}