//###########################################################################
//
// FILE:   sysctl.c
//
// TITLE:  C28x system control driver.
//
//###########################################################################
// 
// C2000Ware v26.00.00.00
//
// Copyright (C) 2024 Texas Instruments Incorporated - http://www.ti.com
//
// Redistribution and use in source and binary forms, with or without 
// modification, are permitted provided that the following conditions 
// are met:
// 
//   Redistributions of source code must retain the above copyright 
//   notice, this list of conditions and the following disclaimer.
// 
//   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.
// 
//   Neither the name of Texas Instruments Incorporated 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 
// OWNER 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 "cputimer.h"
#include "sysctl.h"

//
// Define to isolate inline assembly
//
#define SYSCTL_DELAY        __asm(" .if __TI_EABI__\n"                         \
                                  " .asg    SysCtl_delay    , _SysCtl_delay\n" \
                                  " .endif\n"                                  \
                                  " .def _SysCtl_delay\n"                      \
                                  " .sect \".TI.ramfunc\"\n"                   \
                                  " .global  _SysCtl_delay\n"                  \
                                  "_SysCtl_delay:\n"                           \
                                  " SUB    ACC,#1\n"                           \
                                  " BF     _SysCtl_delay, GEQ\n"               \
                                  " LRETR\n")
#define SYSCTL_CLRC_DBGM    __asm(" CLRC DBGM")

//
// Define Timer1 and Timer2 seed values
//
#define TMR1SYSCLKCTR       0xF0000000U
#define TMR2INPCLKCTR       0x800U

#define XTAL_CPUTIMER_PERIOD 1023U

//*****************************************************************************
//
// SysCtl_delay()
//
//*****************************************************************************
SYSCTL_DELAY;


static void
SysCtl_pollCpuTimer(void)
{
    //
    // Delay for 1 ms while the XTAL powers up
    //
    // 2000 loops, 5 cycles per loop + 9 cycles overhead = 10009 cycles
    //
    SysCtl_delay(2000);

    //
    // Wait for cpu timer 2 to overflow
    //
    while(CPUTimer_getTimerOverflowStatus(CPUTIMER2_BASE) == false);
    {
        //
        // If your application is stuck in this loop, please check if the
        // input clock source is valid.
        //
    }

    //
    // Clear cpu timer 2 overflow flag
    //
    CPUTimer_clearOverflowFlag(CPUTIMER2_BASE);
}

//*****************************************************************************
//
// SysCtl_getClock()
//
//*****************************************************************************
uint32_t
SysCtl_getClock(uint32_t clockInHz)
{
    uint32_t temp;
    uint32_t oscSource;
    uint32_t clockOut;

    //
    // Don't proceed if an MCD failure is detected.
    //
    if(SysCtl_isMCDClockFailureDetected())
    {
        //
        // OSCCLKSRC2 failure detected. Returning the INTOSC1 rate. You need
        // to handle the MCD and clear the failure.
        //
        clockOut = SYSCTL_DEFAULT_OSC_FREQ;
    }
    else
    {
        //
        // If one of the internal oscillators is being used, start from the
        // known default frequency.  Otherwise, use clockInHz parameter.
        //
        oscSource = HWREG(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &
                    (uint32_t)SYSCTL_CLKSRCCTL1_OSCCLKSRCSEL_M;

        if((oscSource == (SYSCTL_OSCSRC_OSC2 >> SYSCTL_OSCSRC_S)) ||
           (oscSource == (SYSCTL_OSCSRC_OSC1 >> SYSCTL_OSCSRC_S)))
        {
            clockOut = SYSCTL_DEFAULT_OSC_FREQ;
        }
        else
        {
            clockOut = clockInHz;
        }

        //
        // If the PLL is enabled calculate its effect on the clock
        //
        if((HWREG(CLKCFG_BASE + SYSCTL_O_SYSPLLCTL1) &
            (SYSCTL_SYSPLLCTL1_PLLEN | SYSCTL_SYSPLLCTL1_PLLCLKEN)) == 3U)
        {
            //
            // Calculate portion from fractional multiplier
            //
            temp = (clockInHz * ((HWREG(CLKCFG_BASE + SYSCTL_O_SYSPLLMULT) &
                                  SYSCTL_SYSPLLMULT_FMULT_M) >>
                                 SYSCTL_SYSPLLMULT_FMULT_S)) / 4U;

            //
            // Calculate integer multiplier and fixed divide by 2
            //
            clockOut = clockOut * ((HWREG(CLKCFG_BASE + SYSCTL_O_SYSPLLMULT) &
                                    SYSCTL_SYSPLLMULT_IMULT_M) >>
                                   SYSCTL_SYSPLLMULT_IMULT_S);

            //
            // Add in fractional portion
            //
            clockOut += temp;
        }

        if((HWREG(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) &
            SYSCTL_SYSCLKDIVSEL_PLLSYSCLKDIV_M) != 0U)
        {
            clockOut /= (2U * (HWREG(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) &
                               SYSCTL_SYSCLKDIVSEL_PLLSYSCLKDIV_M));
        }
    }

    return(clockOut);
}

//*****************************************************************************
//
// SysCtl_getAuxClock()
//
//*****************************************************************************
uint32_t SysCtl_getAuxClock(uint32_t clockInHz)
{
    uint32_t temp;
    uint32_t oscSource;
    uint32_t clockOut;

    oscSource = HWREG(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) &
                (uint32_t)SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_M;

    //
    // If one of the internal oscillators is being used, start from the
    // known default frequency.  Otherwise, use clockInHz parameter.
    //
    if(oscSource == (SYSCTL_AUXPLL_OSCSRC_OSC2 >> SYSCTL_OSCSRC_S))
    {
        //
        // 10MHz Internal Clock
        //
        clockOut = SYSCTL_DEFAULT_OSC_FREQ;
    }
    else
    {
        clockOut = clockInHz;
    }

    //
    // If the PLL is enabled calculate its effect on the clock
    //
    if((HWREG(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) &
        (SYSCTL_AUXPLLCTL1_PLLEN | SYSCTL_AUXPLLCTL1_PLLCLKEN)) == 3U)
    {
        //
        // Calculate portion from fractional multiplier
        //
        temp = (clockInHz * ((HWREG(CLKCFG_BASE + SYSCTL_O_AUXPLLMULT) &
                              SYSCTL_AUXPLLMULT_FMULT_M) >>
                             SYSCTL_AUXPLLMULT_FMULT_S)) / 4U;

        //
        // Calculate integer multiplier
        //
        clockOut = clockOut * ((HWREG(CLKCFG_BASE + SYSCTL_O_AUXPLLMULT) &
                                SYSCTL_AUXPLLMULT_IMULT_M) >>
                               SYSCTL_AUXPLLMULT_IMULT_S);

        //
        // Add in fractional portion
        //
        clockOut += temp;
    }

    clockOut /= (1U << (HWREG(CLKCFG_BASE + SYSCTL_O_AUXCLKDIVSEL) &
                        SYSCTL_AUXCLKDIVSEL_AUXPLLDIV_M));

    return(clockOut);
}

//*****************************************************************************
//
// SysCtl_setClock()
//
//*****************************************************************************
bool
SysCtl_setClock(uint32_t config)
{
    uint16_t divSel;
    uint16_t iMult = 0U, fMult = 0U, pllMult = 0U, div;
    bool status, sysclkInvalidFreq = true;
    uint16_t i, tempSCSR, tempWDCR, tempWDWCR, intStatus;
    uint16_t t1TCR, t1TPR, t1TPRH, t2TCR, t2TPR, t2TPRH, t2CLKCTL;
    uint32_t t1PRD, t2PRD, ctr1;
    float32_t sysclkToInClkError, mult;

    //
    // Check the arguments.
    //
    ASSERT((config & SYSCTL_OSCSRC_M) != SYSCTL_OSCSRC_M); // 3 is not valid

    //
    // Don't proceed to the PLL initialization if an MCD failure is detected.
    //
    if(SysCtl_isMCDClockFailureDetected())
    {
        //
        // OSCCLKSRC2 failure detected. Returning false. You'll need to clear
        // the MCD error.
        //
        status = false;
    }
    else
    {
        //
        // Configure oscillator source
        //
        SysCtl_selectOscSource(config & SYSCTL_OSCSRC_M);

        //
        // Bypass PLL
        //
        EALLOW;
        HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLCTL1) &=
            ~SYSCTL_SYSPLLCTL1_PLLCLKEN;
        EDIS;

        //
        // Delay of at least 120 OSCCLK cycles required post PLL bypass
        //
        SysCtl_delay(23U);

        //
        // Configure PLL if enabled
        //
        EALLOW;
        if((config & SYSCTL_PLL_ENABLE) == SYSCTL_PLL_ENABLE)
        {
            if((HWREGH(DEVCFG_BASE + SYSCTL_O_SYSDBGCTL) &
                SYSCTL_SYSDBGCTL_BIT_0) != 0U)
            {
                //
                // The user can optionally insert handler code here. This will
                // only be executed if a watchdog reset occurred after a failed
                // system PLL initialization. See your device user's guide for
                // more information.
                //
                // If the application has a watchdog reset handler, this bit
                // should be checked to determine if the watchdog reset
                // occurred because of the PLL.
                //
                // No action here will continue with retrying the PLL as
                // normal.
                //
            }

            //
            // Set dividers to /1
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) = 0U;

            //
            // Get the PLL multiplier settings from config
            //
            iMult |= (uint16_t)(config & SYSCTL_IMULT_M);
            fMult |= (uint16_t)((config & SYSCTL_FMULT_M) >> SYSCTL_FMULT_S);
            pllMult |= (iMult << SYSCTL_SYSPLLMULT_IMULT_S) |
                       (fMult << SYSCTL_SYSPLLMULT_FMULT_S);

            //
            // Lock the PLL five times. This helps ensure a successful start.
            // Five is the minimum recommended number. The user can increase
            // this number according to allotted system initialization time.
            //
            for(i = 0U; i < 5U; i++)
            {
                //
                // Turn off PLL
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLCTL1) &=
                    ~SYSCTL_SYSPLLCTL1_PLLEN;

                asm(" RPT #60 || NOP");

                //
                // Write multiplier, which automatically turns on the PLL
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLMULT) = pllMult;

                //
                // Wait for the SYSPLL lock counter
                //
                while((HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLSTS) &
                       SYSCTL_SYSPLLSTS_LOCKS) == 0U)
                {
                    //
                    // Consider to servicing the watchdog using
                    // SysCtl_serviceWatchdog()
                    //
                }
            }
        }

        //
        // Configure Dividers. Set divider to produce slower output frequency
        // to limit current increase.
        //
        divSel = (uint16_t)(config & SYSCTL_SYSDIV_M) >> SYSCTL_SYSDIV_S;

        if(divSel != (126U / 2U))
        {
            HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) =
                (HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) &
                ~(uint16_t)SYSCTL_SYSCLKDIVSEL_PLLSYSCLKDIV_M) | (divSel + 1U);
        }
        else
        {
            HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) =
                (HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) &
                 ~(uint16_t)SYSCTL_SYSCLKDIVSEL_PLLSYSCLKDIV_M) | divSel;
        }

        //
        //      *CAUTION*
        // It is recommended to use the following watchdog code to monitor the
        // PLLstartup sequence. If your application has already cleared the
        // watchdog SCRS[WDOVERRIDE] bit this cannot be done. It is recommended
        // not to clear this bit until after the PLL has been initiated.
        //

        //
        // Backup User Watchdog
        //
        tempSCSR = HWREGH(WD_BASE + SYSCTL_O_SCSR);
        tempWDCR = HWREGH(WD_BASE + SYSCTL_O_WDCR);
        tempWDWCR = HWREGH(WD_BASE + SYSCTL_O_WDWCR);

        //
        // Disable windowed functionality, reset counter
        //
        HWREGH(WD_BASE + SYSCTL_O_WDWCR) = 0x0U;
        SysCtl_serviceWatchdog();

        //
        // Disable global interrupts
        //
        intStatus = __disable_interrupts();

        //
        // Configure for watchdog reset and to run at max frequency
        //
        EALLOW;
        HWREGH(WD_BASE + SYSCTL_O_SCSR) = 0x0U;
        HWREGH(WD_BASE + SYSCTL_O_WDCR) = SYSCTL_WD_CHKBITS;

        //
        // This bit is reset only by power-on-reset (POR) and will not be
        // cleared by a WD reset
        //
        HWREGH(DEVCFG_BASE + SYSCTL_O_SYSDBGCTL) |= SYSCTL_SYSDBGCTL_BIT_0;

        //
        // Enable PLLSYSCLK is fed from system PLL clock
        //
        HWREGH(CLKCFG_BASE +
               SYSCTL_O_SYSPLLCTL1) |= SYSCTL_SYSPLLCTL1_PLLCLKEN;

        EDIS;

        //
        // Delay to ensure system is clocking from PLL prior to clearing
        // status bit
        //
        SysCtl_delay(3U);

        //
        // Slip Bit Monitor and SYSCLK Frequency Check using timers
        // Re-lock routine for SLIP condition or if SYSCLK and CLKSRC timer
        // counts are off by +/- 10%. At a minimum, SYSCLK check is performed.
        // Re-lock attempt is carried out if SLIPS bit is set.
        // This while loop is monitored by watchdog.
        // In the event that the PLL does not successfully lock, the loop will
        // be aborted by watchdog reset.
        //
        while(((config & SYSCTL_PLL_ENABLE) == SYSCTL_PLL_ENABLE) &&
              (sysclkInvalidFreq == true))
        {
            EALLOW;

            //
            // Perform PLL re-lock only if SLIPS bit is set, otherwise monitor
            // SYSCLK frequency with timers
            //
            if((HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLSTS) &
                SYSCTL_SYSPLLSTS_SLIPS) == 1U)
            {
                //
                // Bypass PLL
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLCTL1) &=
                    ~SYSCTL_SYSPLLCTL1_PLLCLKEN;

                //
                // Delay of at least 120 OSCCLK cycles required post PLL bypass
                //
                SysCtl_delay(23U);

                //
                // Turn off PLL
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLCTL1) &=
                    ~SYSCTL_SYSPLLCTL1_PLLEN;

                SysCtl_delay(12U);

                //
                // Write multiplier, which automatically turns on the PLL
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLMULT) |= pllMult;

                //
                // Wait for the SYSPLL lock counter
                //
                while((HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLSTS) &
                        SYSCTL_SYSPLLSTS_LOCKS) == 0U)
                {
                    ;
                }

                //
                // Enable PLLSYSCLK is fed from system PLL clock
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_SYSPLLCTL1) |=
                    SYSCTL_SYSPLLCTL1_PLLCLKEN;

                //
                // Delay to ensure system is clocking from PLL prior to
                // clearing status bit
                //
                SysCtl_delay(12U);
            }

            //
            // Backup timer1 and timer2 settings
            //
            t1TCR = HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR);
            t1PRD = HWREG(CPUTIMER1_BASE + CPUTIMER_O_PRD);
            t1TPR = HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TPR);
            t1TPRH = HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TPRH);
            t2CLKCTL = HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL);
            t2TCR = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR);
            t2PRD = HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD);
            t2TPR = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPR);
            t2TPRH = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPRH);

            //
            // Set up timers 1 and 2
            // Configure timer1 to count SYSCLK cycles
            //

            //
            // Stop timer 1
            // Seed timer1 counter
            // Set sysclock divider
            // Reload timer with value in PRD
            // Clear interrupt flag
            // Enable interrupt
            //
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;
            HWREG(CPUTIMER1_BASE + CPUTIMER_O_PRD) = (uint32_t)TMR1SYSCLKCTR;
            HWREG(CPUTIMER1_BASE + CPUTIMER_O_TPR) = 0U;
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TRB;
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TIF;
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TIE;

            //
            // Configure timer2 to count Input clock cycles
            //
            switch (config & SYSCTL_OSCSRC_M)
            {
                case SYSCTL_OSCSRC_OSC1:
                    //
                    // Clk Src = INT_OSC1
                    //
                    HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) =
                            (HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) &
                             ~SYSCTL_TMR2CLKCTL_TMR2CLKSRCSEL_M) | 1U;
                    break;

                case SYSCTL_OSCSRC_OSC2:
                    //
                    // Clk Src = INT_OSC2
                    //
                    HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) =
                            (HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) &
                             ~SYSCTL_TMR2CLKCTL_TMR2CLKSRCSEL_M) | 2U;
                    break;

                case SYSCTL_OSCSRC_XTAL:
                    //
                    // Clk Src = XTAL
                    //
                    HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) =
                            (HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) &
                             ~SYSCTL_TMR2CLKCTL_TMR2CLKSRCSEL_M) | 3U;
                    break;

                default:
                    //
                    // Do nothing. Not a valid clock source value.
                    //
                    break;
            }

            //
            // Clear interrupt flag
            // Enable interrupt
            // Stop timer 2
            // Seed timer2 counter
            // Set sysclock divider
            // Reload timer with value in PRD
            //
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TIF;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TIE;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;
            HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD) = (uint32_t)TMR2INPCLKCTR;
            HWREG(CPUTIMER2_BASE + CPUTIMER_O_TPR) = 0U;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TRB;

            //
            // Stop/Start timer counters
            //

            //
            // Stop timer 1
            // Stop timer 2
            // Reload timer1 with value in PRD
            // Reload timer2 with value in PRD
            // Clear timer2 interrupt flag
            // Start timer2
            // Start timer1
            //
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TRB;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TRB;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TIF;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) &= ~CPUTIMER_TCR_TSS;
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) &= ~CPUTIMER_TCR_TSS;

            //
            // Wait for Timers - Stop if either timer overflows
            //
            while(((HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) &
                   CPUTIMER_TCR_TIF) == 0U)  &&
                  ((HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) &
                   CPUTIMER_TCR_TIF) == 0U))
            {
                ;
            }

            //
            // Stop timer 1 and 2
            //
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;

            //
            // Calculate elapsed counts on timer1
            //
            ctr1 = (uint32_t)TMR1SYSCLKCTR - HWREG(CPUTIMER1_BASE +
                                                   CPUTIMER_O_TIM);

            //
            // Restore timer settings
            //
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TCR) = t1TCR;
            HWREG(CPUTIMER1_BASE + CPUTIMER_O_PRD) = t1PRD;
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TPR) = t1TPR;
            HWREGH(CPUTIMER1_BASE + CPUTIMER_O_TPRH) = t1TPRH;
            HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) = t2CLKCTL;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) = t2TCR;
            HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD) = t2PRD;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPR) = t2TPR;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPRH) = t2TPRH;

            //
            // Calculate Clock Error:
            // Error = (mult/div) - (timer1 count/timer2 count)
            //
            mult = (float32_t)iMult + ((float32_t)fMult / 4.0F);

            if((HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) & 0x3FU) == 0U)
            {
                div = 1U;
            }
            else
            {
                div = (HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) &
                       0x3FU) << 1;
            }

            sysclkToInClkError = (mult / (float32_t)div) -
                                 ((float32_t)ctr1 / (float32_t)TMR2INPCLKCTR);

            //
            // sysclkInvalidFreq will be set to true if sysclkToInClkError is
            // off by 10%
            //
            sysclkInvalidFreq = ((sysclkToInClkError > 0.10F) ||
                                 (sysclkToInClkError < -0.10F));

            EDIS;
        }

        //
        // Clear bit
        //
        EALLOW;
        HWREGH(DEVCFG_BASE + SYSCTL_O_SYSDBGCTL) &= ~SYSCTL_SYSDBGCTL_BIT_0;
        EDIS;

        //
        // Restore user watchdog, first resetting counter
        //
        SysCtl_serviceWatchdog();

        //
        // Set the KEY bits and make sure not to set the WDOVERRIDE bit
        //
        EALLOW;
        HWREGH(WD_BASE + SYSCTL_O_WDCR) = tempWDCR | SYSCTL_WD_CHKBITS;
        HWREGH(WD_BASE + SYSCTL_O_WDWCR) = tempWDWCR;
        HWREGH(WD_BASE + SYSCTL_O_SCSR) = tempSCSR & ~SYSCTL_SCSR_WDOVERRIDE;
        EDIS;

        //
        // Restore state of ST1[INTM]. This was set by the
        // __disable_interrupts() intrinsic previously.
        //
        if((intStatus & 0x1U) == 0U)
        {
            EINT;
        }

        //
        // Restore state of ST1[DBGM]. This was set by the
        // __disable_interrupts() intrinsic previously.
        //
        if((intStatus & 0x2U) == 0U)
        {
            SYSCTL_CLRC_DBGM;
        }

        //
        // ~200 PLLSYSCLK delay to allow voltage regulator to stabilize prior
        // to increasing entire system clock frequency.
        //
        SysCtl_delay(40U);

        //
        // Set the divider to user value
        //
        EALLOW;
        HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) =
            (HWREGH(CLKCFG_BASE + SYSCTL_O_SYSCLKDIVSEL) &
             ~SYSCTL_SYSCLKDIVSEL_PLLSYSCLKDIV_M) | divSel;
        SYSCTL_REGWRITE_DELAY;
        EDIS;

        status = true;
    }

    return(status);
}
//*****************************************************************************
//
// SysCtl_setAuxClock()
//
//*****************************************************************************
void SysCtl_setAuxClock(uint32_t config)
{
    uint16_t pllMult = 0U;
    uint16_t counter = 0U, started = 0U, attempts = 0U;
    uint16_t mult;
    uint16_t i, t2TCR, t2TPR, t2TPRH, t2CLKCTL;
    uint32_t t2PRD;

    //
    // Check the arguments
    //
    ASSERT((config & SYSCTL_OSCSRC_M) != SYSCTL_OSCSRC_M); // 3 is not valid

    //
    // Bypass PLL
    //
    EALLOW;
    HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) &= ~SYSCTL_AUXPLLCTL1_PLLCLKEN;
    EDIS;

    //
    // Delay of at least 120 OSCCLK cycles required post PLL bypass
    //
    SysCtl_delay(23U);

    //
    // Configure oscillator source
    //
    SysCtl_selectOscSourceAuxPLL(config & SYSCTL_OSCSRC_M);

    //
    // Get the PLL multiplier settings from config
    //
    pllMult |= (uint16_t)((config & SYSCTL_IMULT_M) <<
                          SYSCTL_AUXPLLMULT_IMULT_S);
    pllMult |= (uint16_t)(((config & SYSCTL_FMULT_M) >> SYSCTL_FMULT_S) <<
                          SYSCTL_AUXPLLMULT_FMULT_S);

    //
    // Get the PLL multipliers currently programmed
    //
    mult  = (uint16_t)((HWREG(CLKCFG_BASE + SYSCTL_O_AUXPLLMULT) &
                        (uint32_t)SYSCTL_AUXPLLMULT_IMULT_M) >>
                       (uint32_t)SYSCTL_AUXPLLMULT_IMULT_S);
    mult |= (uint16_t)(HWREG(CLKCFG_BASE + SYSCTL_O_AUXPLLMULT) &
                             SYSCTL_AUXPLLMULT_FMULT_M);

    //
    // Lock PLL only if the multipliers need update
    //
    if(mult !=  pllMult)
    {

        //
        // Configure PLL if enabled
        //
        if((config & SYSCTL_AUXPLL_ENABLE) == SYSCTL_AUXPLL_ENABLE)
        {
            //
            // Backup Timer 2 settings
            //
            t2CLKCTL = HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL);
            t2TCR = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR);
            t2PRD = HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD);
            t2TPR = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPR);
            t2TPRH = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPRH);

            //
            // Configure Timer 2 for AUXPLL as source in known configuration
            // - Clock source to AUXPLL
            // - Clock divider to divide by 1
            // - Small period to detect overflow
            // - Interrupt disabled
            //
            EALLOW;
            HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) = 6U;

            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;

            HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD) = 10U;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPR) = 0U;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPRH) = 0U;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) &= ~CPUTIMER_TCR_TIE;

            //
            // Set AUX Divide by 8 to ensure that AUXPLLCLK <= SYSCLK / 2
            // while using Timer 2
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_AUXCLKDIVSEL) = 0x3U;
            SYSCTL_REGWRITE_DELAY;
            EDIS;

            //
            // Lock the PLL up to five times.
            //CPU Timer 2 will monitor a successful
            // lock and break out of the loop earlier if detected.
            //
            while((counter < 5U) && (started == 0U))
            {
                EALLOW;

                //
                // Turn off AUXPLL and delay for it to power down.
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) &=
                    ~SYSCTL_AUXPLLCTL1_PLLEN;
                SysCtl_delay(3U);

                //
                // Set integer and fractional multiplier, which automatically
                // turns on the PLL
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLMULT) |= pllMult;
                SYSCTL_REGWRITE_DELAY;

                //
                // Enable AUXPLL
                //
                HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) |=
                    SYSCTL_AUXPLLCTL1_PLLEN;
                EDIS;

                //
                // Wait for the AUXPLL lock counter
                //

                while((HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLSTS) &
                       SYSCTL_AUXPLLSTS_LOCKS) != 1U)
                {
                    //
                    // Consider to servicing the watchdog using
                    // SysCtl_serviceWatchdog()
                    //
                }


                //
                // Enable AUXPLLCLK to be fed from AUXPLL
                //
                EALLOW;
                HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) |=
                    SYSCTL_AUXPLLCTL1_PLLCLKEN;
                SysCtl_delay(3U);

                //
                // CPU Timer 2 will now be setup to be clocked from AUXPLLCLK.
                // This is used to test that the PLL has successfully started.
                //
                // Reload and start the timer
                //
                HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TRB;
                HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) &= ~CPUTIMER_TCR_TSS;

                //
                // Check to see timer is counting properly
                //
                for(i = 0U; i < 1000U; i++)
                {
                    //
                    // Check overflow flag
                    //
                    if((HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) &
                        CPUTIMER_TCR_TIF) != 0U)
                    {
                        //
                        // Clear overflow flag
                        //
                        HWREGH(CPUTIMER2_BASE +
                               CPUTIMER_O_TCR) |= CPUTIMER_TCR_TIF;

                        //
                        // Set flag to indicate PLL started and break out of
                        // for-loop
                        //
                        started = 1U;
                        break;
                    }
                }

                //
                // Stop timer
                //
                HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TSS;
                counter++;
                EDIS;
            }

            if(started == 0U)
            {
                //
                // AUX PLL may not have started. Reset multiplier to 0 (bypass
                // PLL).
                //
                EALLOW;
                HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLMULT) = 0U;
                EDIS;

                //
                // The user should put some handler code here based on how
                // this condition should be handled in their application.
                //
                ESTOP0;
            }

            //
            // Restore Timer 2 configuration
            //
            EALLOW;
            HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) = t2CLKCTL;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) = t2TCR;
            HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD) = t2PRD;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPR) = t2TPR;
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPRH) = t2TPRH;

            //
            // Reload period value
            //
            HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TRB;
            EDIS;
        }
    }
    else
    {
        //
        // Enable AUXPLLCLK to be fed from AUXPLL
        //
        EALLOW;
        HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) |= SYSCTL_AUXPLLCTL1_PLLCLKEN;
        SysCtl_delay(3U);
        EDIS;
    }

    //
    // Slip Bit Monitor
    // Re-lock routine for SLIP condition
    //
    while(((HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLSTS) &
            SYSCTL_AUXPLLSTS_SLIPS) != 0U) && (attempts < 10U) &&
          ((config & SYSCTL_AUXPLL_ENABLE) == SYSCTL_AUXPLL_ENABLE))
    {
        EALLOW;

        //
        // Bypass AUXPLL
        //
        HWREGH(CLKCFG_BASE +
               SYSCTL_O_AUXPLLCTL1) &= ~SYSCTL_AUXPLLCTL1_PLLCLKEN;

        //
        // Delay of at least 120 OSCCLK cycles required post PLL bypass
        //
        SysCtl_delay(23U);

        //
        // Turn off AUXPLL
        //
        HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) &= ~SYSCTL_AUXPLLCTL1_PLLEN;
        SysCtl_delay(3U);

        //
        // Set integer and fractional multiplier, which automatically turns
        // on the PLL
        //
        HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLMULT) |= pllMult;

        //
        // Enable AUXPLL
        //
        HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) |= SYSCTL_AUXPLLCTL1_PLLEN;

        //
        // Wait for the AUXPLL lock counter
        //
        while((HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLSTS) &
               SYSCTL_AUXPLLSTS_LOCKS) != 1U)
        {
            //
            // Consider to servicing the watchdog using
            // SysCtl_serviceWatchdog()
            //
        }

        //
        // Enable AUXPLLCLK to be fed from AUXPLL
        //
        HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) |= SYSCTL_AUXPLLCTL1_PLLCLKEN;

        SysCtl_delay(3U);

        attempts++;

        EDIS;
    }

    //
    // Set divider to desired value
    //
    EALLOW;
    HWREGH(CLKCFG_BASE + SYSCTL_O_AUXCLKDIVSEL) =
        (uint16_t)(config & SYSCTL_SYSDIV_M) >> SYSCTL_SYSDIV_S;
    SYSCTL_REGWRITE_DELAY;
    EDIS;

}


//*****************************************************************************
//
// SysCtl_selectXTAL()
//
//*****************************************************************************
void
SysCtl_selectXTAL(void)
{
    uint16_t t2TCR, t2TPR, t2TPRH, t2CLKCTL;
    uint32_t t2PRD;

    //
    // Backup CPU timer2 settings
    //
    t2CLKCTL = HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL);
    t2TCR = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR);
    t2PRD = HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD);
    t2TPR = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPR);
    t2TPRH = HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPRH);

    //
    // Backup AUX clock settings
    //
    uint16_t clksrcctl2 = HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2);
    uint16_t auxpllctl1 = HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1);
    uint16_t auxclkdivsel = HWREGH(CLKCFG_BASE + SYSCTL_O_AUXCLKDIVSEL);

    //
    // Set AUX clock source to XTAL, bypass mode.
    // AUXCLK is used as the CPUTimer Clock source. SYSCLK frequency must be
    // atleast twice the frequency of AUXCLK. SYSCLK = INTOSC2(10MHz)
    // Set the AUX divider to 8. The above condition will be met for XTAL
    // frequencies up to 40MHz
    //
    EALLOW;
    HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) =
            (HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) &
             ~(SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_M)) |
            (1U << SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_S);
    HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) = 0x0U;
    HWREGH(CLKCFG_BASE + SYSCTL_O_AUXCLKDIVSEL) = SYSCTL_AUXPLLCLK_DIV_8;
    SYSCTL_REGWRITE_DELAY;


    //
    // Disable cpu timer 2 interrupt
    //
    CPUTimer_disableInterrupt(CPUTIMER2_BASE);

    //
    // Stop cpu timer 2 if running
    //
    CPUTimer_stopTimer(CPUTIMER2_BASE);

    //
    // Initialize cpu timer 2 period
    //
    CPUTimer_setPeriod(CPUTIMER2_BASE, XTAL_CPUTIMER_PERIOD);

    //
    // Set cpu timer 2 clock source to XTAL
    //
    CPUTimer_selectClockSource(CPUTIMER2_BASE, CPUTIMER_CLOCK_SOURCE_AUX,
                               CPUTIMER_CLOCK_PRESCALER_1);

    //
    // Clear cpu timer 2 overflow flag
    //
    CPUTimer_clearOverflowFlag(CPUTIMER2_BASE);

    //
    // Start cpu timer 2
    //
    CPUTimer_startTimer(CPUTIMER2_BASE);

    EALLOW;
    //
    // Turn on XTAL
    //
    HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &= ~SYSCTL_CLKSRCCTL1_XTALOFF;
    EDIS;

    //
    // Wait for the X1 clock to overflow cpu timer 2
    //
    SysCtl_pollCpuTimer();

    //
    // Select XTAL as the oscillator source
    //
    EALLOW;
    HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) =
    ((HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &
      (~SYSCTL_CLKSRCCTL1_OSCCLKSRCSEL_M)) |
     (SYSCTL_OSCSRC_XTAL >> SYSCTL_OSCSRC_S));
    EDIS;

    //
    // If a missing clock failure was detected, try waiting for the cpu timer 2
    // to overflow again.
    //
    while(SysCtl_isMCDClockFailureDetected())
    {
        //
        // Clear the MCD failure
        //
        SysCtl_resetMCD();

        //
        // Wait for the X1 clock to overflow cpu timer 2
        //
        SysCtl_pollCpuTimer();

        //
        // Select XTAL as the oscillator source
        //
        EALLOW;
        HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) =
        ((HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &
          (~SYSCTL_CLKSRCCTL1_OSCCLKSRCSEL_M)) |
         (SYSCTL_OSCSRC_XTAL >> SYSCTL_OSCSRC_S));
        EDIS;
    }

    //
    // Stop cpu timer 2
    //
    CPUTimer_stopTimer(CPUTIMER2_BASE);

    //
    // Restore Timer 2 configuration
    //
    EALLOW;
    HWREGH(CPUSYS_BASE + SYSCTL_O_TMR2CLKCTL) = t2CLKCTL;
    HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) = t2TCR;
    HWREG(CPUTIMER2_BASE + CPUTIMER_O_PRD) = t2PRD;
    HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPR) = t2TPR;
    HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TPRH) = t2TPRH;
    HWREGH(CPUTIMER2_BASE + CPUTIMER_O_TCR) |= CPUTIMER_TCR_TRB;

    //
    // Restore AUX clock settings
    //
    HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) = clksrcctl2;
    HWREGH(CLKCFG_BASE + SYSCTL_O_AUXPLLCTL1) = auxpllctl1;
    HWREGH(CLKCFG_BASE + SYSCTL_O_AUXCLKDIVSEL) = auxclkdivsel;
    SYSCTL_REGWRITE_DELAY;
    EDIS;

    EDIS;
}

//*****************************************************************************
//
// SysCtl_selectOscSource()
//
//*****************************************************************************
void
SysCtl_selectOscSource(uint32_t oscSource)
{
    ASSERT((oscSource == SYSCTL_OSCSRC_OSC1) ||
           (oscSource == SYSCTL_OSCSRC_OSC2) ||
           (oscSource == SYSCTL_OSCSRC_XTAL));

    //
    // Select the specified source.
    //
    EALLOW;
    switch(oscSource)
    {
        case SYSCTL_OSCSRC_OSC2:
            //
            // Turn on INTOSC2
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &=
                ~SYSCTL_CLKSRCCTL1_INTOSC2OFF;

            SYSCTL_CLKSRCCTL_DELAY;

            //
            // Clk Src = INTOSC2
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &=
                ~SYSCTL_CLKSRCCTL1_OSCCLKSRCSEL_M;

            SYSCTL_CLKSRCCTL_DELAY;

            //
            // Turn off XTALOSC
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) |=
                SYSCTL_CLKSRCCTL1_XTALOFF;

            break;

        case SYSCTL_OSCSRC_XTAL:
            //
            // Select XTAL in crystal mode and wait for it to power up
            //
            SysCtl_selectXTAL();
            break;

        case SYSCTL_OSCSRC_OSC1:
            //
            // Clk Src = INTOSC1
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) =
                   (HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &
                    ~SYSCTL_CLKSRCCTL1_OSCCLKSRCSEL_M) |
                   (SYSCTL_OSCSRC_OSC1 >> SYSCTL_OSCSRC_S);

            SYSCTL_CLKSRCCTL_DELAY;

            //
            //Turn off XTALOSC
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) |=
                SYSCTL_CLKSRCCTL1_XTALOFF;

            break;

        default:
            //
            // Do nothing. Not a valid oscSource value.
            //
            break;
    }
    EDIS;
}

//*****************************************************************************
//
// SysCtl_selectOscSourceAuxPLL()
//
//*****************************************************************************
void
SysCtl_selectOscSourceAuxPLL(uint32_t oscSource)
{
    bool status = false;

    EALLOW;

    switch(oscSource)
    {
        case SYSCTL_AUXPLL_OSCSRC_OSC2:
            //
            // Turn on INTOSC2
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &=
                    ~(SYSCTL_CLKSRCCTL1_INTOSC2OFF);
            SYSCTL_CLKSRCCTL_DELAY;

            //
            // Clk Src = INTOSC2
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) &=
                    ~(SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_M);
            break;

        case SYSCTL_AUXPLL_OSCSRC_XTAL:
            //
            // Turn on XTALOSC
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL1) &=
                   ~(SYSCTL_CLKSRCCTL1_XTALOFF);
            SYSCTL_CLKSRCCTL_DELAY;

            //
            // Clk Src = XTAL
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) =
                    (HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) &
                     ~(SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_M)) |
                    (1U << SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_S);
            break;

        case SYSCTL_AUXPLL_OSCSRC_AUXCLKIN:
            //
            // Clk Src = AUXCLKIN
            //
            HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) =
                    (HWREGH(CLKCFG_BASE + SYSCTL_O_CLKSRCCTL2) &
                     ~(SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_M)) |
                    (2U << SYSCTL_CLKSRCCTL2_AUXOSCCLKSRCSEL_S);
            SYSCTL_CLKSRCCTL_DELAY;
            break;

        default:
            //
            // Do nothing. Not a valid clock source value.
            //
            break;
    }
    EDIS;
}

//*****************************************************************************
//
// SysCtl_getLowSpeedClock()
//
//*****************************************************************************
uint32_t
SysCtl_getLowSpeedClock(uint32_t clockInHz)
{
    uint32_t clockOut;

    //
    // Get the main system clock
    //
    clockOut = SysCtl_getClock(clockInHz);

    //
    // Apply the divider to the main clock
    //
    if((HWREG(CLKCFG_BASE + SYSCTL_O_LOSPCP) &
        SYSCTL_LOSPCP_LSPCLKDIV_M) != 0U)
    {
        clockOut /= (2U * (HWREG(CLKCFG_BASE + SYSCTL_O_LOSPCP) &
                            SYSCTL_LOSPCP_LSPCLKDIV_M));
    }

    return(clockOut);
}

//*****************************************************************************
//
// SysCtl_getDeviceParametric()
//
//*****************************************************************************
uint16_t
SysCtl_getDeviceParametric(SysCtl_DeviceParametric parametric)
{
    uint32_t value;

    //
    // Get requested parametric value
    //
    switch(parametric)
    {
        case SYSCTL_DEVICE_QUAL:
            //
            // Qualification Status
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDL) &
                      SYSCTL_PARTIDL_QUAL_M) >> SYSCTL_PARTIDL_QUAL_S);
            break;

        case SYSCTL_DEVICE_PINCOUNT:
            //
            // Pin Count
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDL) &
                      SYSCTL_PARTIDL_PIN_COUNT_M) >>
                     SYSCTL_PARTIDL_PIN_COUNT_S);
            break;

        case SYSCTL_DEVICE_INSTASPIN:
            //
            // InstaSPIN Feature Set
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDL) &
                      SYSCTL_PARTIDL_INSTASPIN_M) >>
                     SYSCTL_PARTIDL_INSTASPIN_S);
            break;

        case SYSCTL_DEVICE_FLASH:
            //
            // Flash Size (KB)
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDL) &
                      SYSCTL_PARTIDL_FLASH_SIZE_M) >>
                     SYSCTL_PARTIDL_FLASH_SIZE_S);
            break;

        case SYSCTL_DEVICE_PARTID:
            //
            // PARTID Format Revision
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDL) &
                      SYSCTL_PARTIDL_PARTID_FORMAT_REVISION_M) >>
                     SYSCTL_PARTIDL_PARTID_FORMAT_REVISION_S);
            break;

        case SYSCTL_DEVICE_FAMILY:
            //
            // Device Family
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDH) &
                      SYSCTL_PARTIDH_FAMILY_M) >> SYSCTL_PARTIDH_FAMILY_S);
            break;

        case SYSCTL_DEVICE_PARTNO:
            //
            // Part Number
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDH) &
                      SYSCTL_PARTIDH_PARTNO_M) >> SYSCTL_PARTIDH_PARTNO_S);
            break;

        case SYSCTL_DEVICE_CLASSID:
            //
            // Class ID
            //
            value = ((HWREG(DEVCFG_BASE + SYSCTL_O_PARTIDH) &
                      SYSCTL_PARTIDH_DEVICE_CLASS_ID_M) >>
                     SYSCTL_PARTIDH_DEVICE_CLASS_ID_S);
            break;

        default:
            //
            // Not a valid value for PARTID register
            //
            value = 0U;
            break;
    }

    return((uint16_t)value);
}

