WatchDog Problem

Sir,

In the code given below,it works nicely when timing is 100ms but if i increase the time to 1000 ms it doesn't work.But the same code works for 1000 ms if i work without Watch dog timer.according to what i understood about watchdog timer is that it resent the controller after 4.65ms. But in this code we are stuck for 100ms second inside while(1) at Cputimer0 So, it should continuously keep resetting as code stuck for 100ms at one point.In short, code should for work for 100ms.

For more 100ms we have also put WDKY=0x55 inside the while for cputimer0 it work.but i don't know why?? 

I am pretty sure i understood something wrong.Could anyone can help please to clarify my this confusion

//
// Lab6: TMS320F28335
// (c) Frank Bormann
//
//###########################################################################
//
// FILE: Lab6.c
//
// TITLE: DSP28335ControlCARD; Digital Output
// 4 - bit - counter at 4 LEDs LD1(GPIO9), LD2(GPIO11), LD3(GPIO34)
// and LD4 (GPIO49)
// CPU Timer 0 period and Interrupt Service
// solution file for Lab6
//###########################################################################
// Ver | dd mmm yyyy | Who | Description of changes
// =====|=============|======|===============================================
// 3.0 | 02 May 2008 | F.B. | Lab6 for F28335;
// 3.1 | 08 Nov 2009 | F.B | Lab6 for F28335 and PE revision5
//###########################################################################
#include "DSP2833x_Device.h"

// external function prototypes
extern void InitSysCtrl(void);
extern void InitPieCtrl(void);
extern void InitPieVectTable(void);
extern void InitCpuTimers(void);
extern void ConfigCpuTimer(struct CPUTIMER_VARS *, float, float);

// Prototype statements for functions found within this file.
void Gpio_select(void);
interrupt void cpu_timer0_isr(void);

//###########################################################################
// main code
//###########################################################################
void main(void)
{
int counter=0; // binary counter for digital output

InitSysCtrl(); // Basic Core Init from DSP2833x_SysCtrl.c

EALLOW;
SysCtrlRegs.WDCR= 0x00AF; // Re-enable the watchdog
EDIS; // 0x00AF to NOT disable the Watchdog, Prescaler = 64

DINT; // Disable all interrupts

Gpio_select(); // GPIO9, GPIO11, GPIO34 and GPIO49 as output
// to 4 LEDs at Peripheral Explorer)

InitPieCtrl(); // basic setup of PIE table; from DSP2833x_PieCtrl.c

InitPieVectTable(); // default ISR's in PIE

EALLOW;
PieVectTable.TINT0 = &cpu_timer0_isr;
EDIS;

InitCpuTimers(); // basic setup CPU Timer0, 1 and 2

ConfigCpuTimer(&CpuTimer0,150,100000); // CPU - Timer0 at 100 milliseconds

PieCtrlRegs.PIEIER1.bit.INTx7 = 1;

IER |=1;

EINT;
ERTM;

CpuTimer0Regs.TCR.bit.TSS = 0; // start timer0

while(1)
{
while(CpuTimer0.InterruptCount == 0);
CpuTimer0.InterruptCount = 0;

EALLOW;
SysCtrlRegs.WDKEY = 0x55; // service WD #1
EDIS;

counter++;
if(counter&1) GpioDataRegs.GPASET.bit.GPIO9 = 1;
else GpioDataRegs.GPACLEAR.bit.GPIO9 = 1;
if(counter&2) GpioDataRegs.GPASET.bit.GPIO11 = 1;
else GpioDataRegs.GPACLEAR.bit.GPIO11 = 1;
if(counter&4) GpioDataRegs.GPBSET.bit.GPIO34 = 1;
else GpioDataRegs.GPBCLEAR.bit.GPIO34 = 1;
if(counter&8) GpioDataRegs.GPBSET.bit.GPIO49 = 1;
else GpioDataRegs.GPBCLEAR.bit.GPIO49 = 1;
}
}

void Gpio_select(void)
{
EALLOW;
GpioCtrlRegs.GPAMUX1.all = 0; // GPIO15 ... GPIO0 = General Puropse I/O
GpioCtrlRegs.GPAMUX2.all = 0; // GPIO31 ... GPIO16 = General Purpose I/O
GpioCtrlRegs.GPBMUX1.all = 0; // GPIO47 ... GPIO32 = General Purpose I/O
GpioCtrlRegs.GPBMUX2.all = 0; // GPIO63 ... GPIO48 = General Purpose I/O
GpioCtrlRegs.GPCMUX1.all = 0; // GPIO79 ... GPIO64 = General Purpose I/O
GpioCtrlRegs.GPCMUX2.all = 0; // GPIO87 ... GPIO80 = General Purpose I/O

GpioCtrlRegs.GPADIR.all = 0;
GpioCtrlRegs.GPADIR.bit.GPIO9 = 1; // peripheral explorer: LED LD1 at GPIO9
GpioCtrlRegs.GPADIR.bit.GPIO11 = 1; // peripheral explorer: LED LD2 at GPIO11

GpioCtrlRegs.GPBDIR.all = 0; // GPIO63-32 as inputs
GpioCtrlRegs.GPBDIR.bit.GPIO34 = 1; // peripheral explorer: LED LD3 at GPIO34
GpioCtrlRegs.GPBDIR.bit.GPIO49 = 1; // peripheral explorer: LED LD4 at GPIO49
GpioCtrlRegs.GPCDIR.all = 0; // GPIO87-64 as inputs
EDIS;
}

interrupt void cpu_timer0_isr(void)
{
CpuTimer0.InterruptCount++;
EALLOW;
SysCtrlRegs.WDKEY = 0xAA; // service WD #2
EDIS;
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
}
//===========================================================================
// End of SourceCode.
//===========================================================================