TM4C1231H6PZ: Internal Flash Erase

Hi Jacob,

  The bootloader will call the ConfigureDevice() function to configure the clock using the main oscillator if the CRYSTAL_FREQ is defined. The CRYSTAL_FREQ is defined in the bl_config.h file. You will need to comment out the #define CRYSTAL_FREQ so that the ConfigureDevice() will not configure the system clock using the main oscillator. 

//*****************************************************************************
//
// The frequency of the crystal used to clock the microcontroller.
//
// This defines the crystal frequency used by the microcontroller running the
// boot loader. If this is unknown at the time of production, then use the
// UART_AUTOBAUD feature to properly configure the UART.
//
// Depends on: None
// Exclusive of: None
// Requires: None
//
//*****************************************************************************
#define CRYSTAL_FREQ 16000000

void
ConfigureDevice(void)
{
#ifdef UART_ENABLE_UPDATE
    uint32_t ui32ProcRatio;
#endif

#ifdef CRYSTAL_FREQ
    //
    // Since the crystal frequency was specified, enable the main oscillator
    // and clock the processor from it.
    //
#if defined(TARGET_IS_TM4C129_RA0) ||                                         \
    defined(TARGET_IS_TM4C129_RA1) ||                                         \
    defined(TARGET_IS_TM4C129_RA2)
    //
    // Since the crystal frequency was specified, enable the main oscillator
    // and clock the processor from it. Check for whether the Oscillator range
    // has to be set and wait states need to be updated
    //
    if(CRYSTAL_FREQ >= 10000000)
    {
        HWREG(SYSCTL_MOSCCTL) |= (SYSCTL_MOSCCTL_OSCRNG);
        HWREG(SYSCTL_MOSCCTL) &= ~(SYSCTL_MOSCCTL_PWRDN |
                                   SYSCTL_MOSCCTL_NOXTAL);
    }
    else
    {
        HWREG(SYSCTL_MOSCCTL) &= ~(SYSCTL_MOSCCTL_PWRDN |
                                   SYSCTL_MOSCCTL_NOXTAL);
    }

    //
    // Wait for the Oscillator to Stabilize
    //
    Delay(524288);

    if(CRYSTAL_FREQ > 16000000)
    {
        HWREG(SYSCTL_MEMTIM0)  = (SYSCTL_MEMTIM0_FBCHT_1_5 |
                                  (1 << SYSCTL_MEMTIM0_FWS_S) |
                                  SYSCTL_MEMTIM0_EBCHT_1_5 |
                                  (1 << SYSCTL_MEMTIM0_EWS_S) |
                                  SYSCTL_MEMTIM0_MB1);
        HWREG(SYSCTL_RSCLKCFG) = (SYSCTL_RSCLKCFG_MEMTIMU |
                                  SYSCTL_RSCLKCFG_OSCSRC_MOSC);
    }
    else
    {
        HWREG(SYSCTL_RSCLKCFG) = (SYSCTL_RSCLKCFG_OSCSRC_MOSC);
    }
#else
    HWREG(SYSCTL_RCC) &= ~(SYSCTL_RCC_MOSCDIS);
    Delay(524288);
    HWREG(SYSCTL_RCC) = ((HWREG(SYSCTL_RCC) & ~(SYSCTL_RCC_OSCSRC_M)) |
                         SYSCTL_RCC_OSCSRC_MAIN);
#endif
#endif