Device sometimes locks up when going into Halt LPM mode

I didn't want to post too much code but below is all of the initialization before the main loop where WAKEINT is enabled.  The LPM mode seems to work a majority of the time.  I can go into and out of halt mode.  Occasionally, it will get stuck.  I was hoping something obvious would stand out.  It's been difficult to pinpoint exactly where the freeze occurs since my connection gets hosed up when the device freezes.  Here is the code, thanks:

int main(int argc, char *argv[])

{

// Initialize System Control:

// PLL, WatchDog, enable Peripheral Clocks

   InitSysCtrl();

   EALLOW;

   #define ADC_MODCLK 0x3 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 150/(2*3)   = 25.0 MHz

   EDIS;

// Clear all interrupts and initialize PIE vector table:

// Disable CPU interrupts

   DINT;

// Initialize the PIE control registers to their default state.

// The default state is all PIE interrupts disabled and flags

// are cleared.

// This function is found in the DSP2833x_PieCtrl.c file.

   InitPieCtrl();

   InitI2CGpio();

// Disable CPU interrupts and clear all CPU interrupt flags:

   IER = 0x0000;

   IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt

// Service Routines (ISR).

// This will populate the entire table, even if the interrupt

// is not used in this example.  This is useful for debug purposes

// The shell ISR routines are found in DSP2833x_DefaultIsr.c.

// This function is found in DSP2833x_PieVect.c.

   InitPieVectTable();

// Interrupts that are used in this example are re-mapped to

// ISR functions found within this file.

   EALLOW;  // This is needed to write to EALLOW protected register

   PieVectTable.ADCINT = &adc_isr;

   PieVectTable.I2CINT1A = &i2c_int1a_isr;

   PieVectTable.TINT2 = &cpu_timer2_isr;

   PieVectTable.XINT13 = &cpu_timer1_isr;

   PieVectTable.ECAP1_INT = &ecap1_isr;

   PieVectTable.WAKEINT = &WAKE_ISR;

   EDIS;    // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:

// This function is found in DSP2833x_InitPeripherals.c

// InitPeripherals(); // Not required for this example

// Copy time critical code and Flash setup code to RAM

// This includes the following ISR functions: epwm1_timer_isr(), epwm2_timer_isr()

// epwm3_timer_isr and and InitFlash();

// The  RamfuncsLoadStart, RamfuncsLoadEnd, and RamfuncsRunStart

// symbols are created by the linker. Refer to the F28335.cmd file.

   //MemCopy(&RamfuncsLoadStart, &RamfuncsLoadEnd, &RamfuncsRunStart);

// Call Flash Initialization to setup flash waitstates

// This function must reside in RAM

   //InitFlash();

   SetupGPIO();

   InitECapture();

   InitECap1Gpio();

   I2C_Init();

   InitObjects();

   InitSpiaGpio();

   InitScibGpio();

   DAC_WTM();

   //ConfigDigipot();

// Step 5. User specific code, enable interrupts:

   InitCpuTimers();

   ConfigCpuTimer(&CpuTimer1, 150, 10); //10us

   ConfigCpuTimer(&CpuTimer2, 150, 1000000);   //1 sec 

   GpioDataRegs.GPACLEAR.bit.GPIO0 = 1; //disable buzzer until PWM initialized

// To ensure precise timing, use write-only instructions to write to the entire register. Therefore, if any

// of the configuration bits are changed in ConfigCpuTimer and InitCpuTimers (in DSP2833x_CpuTimers.h), the

// below settings must also be updated.

// Enable ADCINT in PIE

   CpuTimer2Regs.TCR.all = 0x4001;

   CpuTimer1Regs.TCR.all = 0x4001; 

   PieCtrlRegs.PIEIER1.bit.INTx6 = 1;

   // Enable I2C interrupt 1 in the PIE: Group 8 interrupt 1

   PieCtrlRegs.PIEIER8.bit.INTx1 = 1;   

// Enable eCAP INTn in the PIE: Group 3 interrupt 1-6

   PieCtrlRegs.PIEIER4.bit.INTx1 = 1;

 // Enable WAKEINT in the PIE: Group 1 interrupt 8

   PieCtrlRegs.PIEIER1.bit.INTx8 = 1;

   PieCtrlRegs.PIEACK.bit.ACK1 = 1;

   IER |= M_INT1; //timer 0

   IER |= M_INT13;  //timer 1

   IER |= M_INT8;

   IER |= M_INT14; //timer 2

   IER |= M_INT4; //ECAP

   EINT;          // Enable Global interrupt INTM

   ERTM;          // Enable Global realtime interrupt DBGM

   // Write the LPM code value

    EALLOW;

if (SysCtrlRegs.PLLSTS.bit.MCLKSTS != 1) // Only enter low power mode when PLL is not in limp mode.

{

      SysCtrlRegs.LPMCR0.bit.LPM = 0x0002;   // LPM mode = Halt

    }

    EDIS;

GasGauge.reg[2] = 0xFF;

GasGauge.reg[3] = 0xFF;

InitProx();

    ConfigureADC();

    InitAdc();  // Init the ADC

    InitEPwm1();

    scia_fifo_init();

scia_echoback_init();

   init_power();

   Init_LEDs();

   Init_Accel();

   AllOff();

if(GpioDataRegs.GPCDAT.bit.GPIO73 == 0) //special mode to reset GG, mute button pressed when powering up

{

WriteGGRegister(2,0xFF);

while(I2cMsgOut1.MsgStatus != I2C_MSGSTAT_INACTIVE&&I2cMsgOut1.MsgStatus != I2C_MSGSTAT_SEND_WITHSTOP);

WriteGGRegister(3,0xFF);

while(I2cMsgOut1.MsgStatus != I2C_MSGSTAT_INACTIVE&&I2cMsgOut1.MsgStatus != I2C_MSGSTAT_SEND_WITHSTOP);

Quickbeep(1);

}

if(GpioDataRegs.GPCDAT.bit.GPIO72 == 0) //special mode to disable LPM counter

{

LPM_enabled = false;

Quickbeep(1);

}

if(vib_enabled)Quickbuzz(3);

else Quickbeep(4);

autoWindow();

zeroFlag = 1;

// Wait for interrut

   for(;;)

   {

   }

Jason,

It could be that the device is not coming out of HALT mode. We have never seen an instance when the device is unable to enter HALT mode (unless the wakeup signal is noisy and pulls the device out of HALT right away). You could easily confirm if the device is in HALT by the drop in current requirement. Not usre if this is possible if the board is already designed and there is no hook to stick a meter in. if there is a ferrite bead in series with the supply lines, you could remove it and stick a meter in. If the wakeup signal is noisy, it may lead to the part being stuck in HALT. Please ensure the pin used for wakeup is noise-free both while entering and exiting HALT.