Watchdog period in TMS320F28377S

Hi,

Your understanding about the maximum time for WD counter to overflow to reset the device is correct. What's the time you are observing? 

Please share the code you are using for WD configuration.

Regards,

Vivek Singh

Vivek Singh, thanks for the reply.

The complete code is bellow and is taken from a tutorial, which uses the timer0 interrupts as exercise.
Except for the function Gpio_select(), all others are functions provided by TI.
I use the ConfigCpuTimer(&CpuTimer0, 200, 440000) to set the timer0 period. The limit is 440 ms. If put 450 ms, occurs Watchdog reset.
As you can see, I set the watchdog prescaler to maximum by writing WdRegs.WDCR.all = 0x00AF. So, by the calculations, I have ~ 830 ms and should not occur a restart.
So what am I doing wrong?
I'm using Code Composer Studio 6.1.2.00015, Compiler Version TI v15.12.1.LTS.

//#include "F2837xS_device.h"     // F2837xS Headerfile Include File
#include "F28x_Project.h"     // Device Headerfile and Examples Include File

// 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 Initialization

	DINT;				// Disable all interrupts
	
	Gpio_select();		// GPIO9,GPIO11,GPIO34 and GPIO49 as output (LEDs @ peripheral explorer)

	InitPieCtrl();

	InitPieVectTable();

	EALLOW;  // This is needed to write to EALLOW protected registers
	PieVectTable.TIMER0_INT = &cpu_timer0_isr;
	WdRegs.WDCR.all = 0x00AF;							// Enable watchdog
	EDIS;    // This is needed to disable write to EALLOW protected registers

	InitCpuTimers();

	ConfigCpuTimer(&CpuTimer0, 200, 400000);

	PieCtrlRegs.PIEIER1.bit.INTx7 = 1;
	IER |= 1;

    // Enable global Interrupts and higher priority real-time debug events:
    EINT;  // Enable Global interrupt INTM
    ERTM;  // Enable Global realtime interrupt DBGM

	CpuTimer0Regs.TCR.bit.TSS = 0;

	while(1)
	{    
	  		counter++;
	  		if ((counter&0x1) == 1) GpioDataRegs.GPASET.bit.GPIO12 = 1;
	  		else  GpioDataRegs.GPACLEAR.bit.GPIO12 = 1;
	  		if ((counter&0x2) == 2) GpioDataRegs.GPASET.bit.GPIO13 = 1;
	  		else  GpioDataRegs.GPACLEAR.bit.GPIO13 = 1;
	  		if ((counter&0x4) == 4) GpioDataRegs.GPASET.bit.GPIO14 = 1;
	  		else  GpioDataRegs.GPACLEAR.bit.GPIO14 = 1;
	  		if ((counter&0x8) == 8) GpioDataRegs.GPASET.bit.GPIO15 = 1;
	  		else  GpioDataRegs.GPACLEAR.bit.GPIO15 = 1;

	  		EALLOW;
			WdRegs.WDKEY.bit.WDKEY = 0x55;
			EDIS;

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


			// place your code to analyze counter here 
			// if bit 0 of counter = 1, set GPIO9 to 1
			// if bit 1 of counter = 1, set GPIO11 to 1 
			// if bit 2 of counter = 1, set GPIO34 to 1
			// if bit 3 of counter = 1, set GPIO49 to 1 
	}
} 

__interrupt void cpu_timer0_isr(void)
{
	EALLOW;
	WdRegs.WDKEY.bit.WDKEY = 0xAA;
	EDIS;
	CpuTimer0.InterruptCount++;
	PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
}

void Gpio_select(void)
{
	EALLOW;

	// Set up all multiplex register to digital I/O.
	GpioCtrlRegs.GPAGMUX1.all = 0x0;
	GpioCtrlRegs.GPAGMUX2.all = 0x0;
	GpioCtrlRegs.GPBGMUX1.all = 0x0;
	GpioCtrlRegs.GPBGMUX2.all = 0x0;
	GpioCtrlRegs.GPCGMUX1.all = 0x0;
	GpioCtrlRegs.GPCGMUX2.all = 0x0;
	GpioCtrlRegs.GPDGMUX1.all = 0x0;
	GpioCtrlRegs.GPDGMUX2.all = 0x0;
	GpioCtrlRegs.GPEGMUX1.all = 0x0;
	GpioCtrlRegs.GPEGMUX2.all = 0x0;
	GpioCtrlRegs.GPFGMUX1.all = 0x0;

	GpioCtrlRegs.GPAMUX1.all = 0x0;
	GpioCtrlRegs.GPAMUX2.all = 0x0;
	GpioCtrlRegs.GPBMUX1.all = 0x0;
	GpioCtrlRegs.GPBMUX2.all = 0x0;
	GpioCtrlRegs.GPCMUX1.all = 0x0;
	GpioCtrlRegs.GPCMUX2.all = 0x0;
	GpioCtrlRegs.GPDMUX1.all = 0x0;
	GpioCtrlRegs.GPDMUX2.all = 0x0;
	GpioCtrlRegs.GPEMUX1.all = 0x0;
	GpioCtrlRegs.GPEMUX2.all = 0x0;
	GpioCtrlRegs.GPFMUX1.all = 0x0;

	// Set up GPADIR: lines GPIO12, GPIO13, GPIO14 e GPIO15  to output and all other lines to input.
	GpioCtrlRegs.GPADIR.all = 0x0000F000;
	//GpioCtrlRegs.GPADIR.bit.GPIO12 = 1;   // GPIO12 = output
	//GpioCtrlRegs.GPADIR.bit.GPIO13 = 1;   // GPIO13 = output
	//GpioCtrlRegs.GPADIR.bit.GPIO14 = 1;   // GPIO14 = output
	//GpioCtrlRegs.GPADIR.bit.GPIO15 = 1;   // GPIO15 = output


	EDIS;

}   
//===========================================================================
// End of SourceCode.
//===========================================================================

I found out what's wrong.

I did a Step In inside the InitSysCtrl() function and the part that sets the clock speed is:

    // Initialize the PLL control: PLLCR and CLKINDIV
    // F28_PLLCR and F28_CLKINDIV are defined in F2837xS_Examples.h
    // Note: The internal oscillator CANNOT be used as the PLL source if the
    // PLLSYSCLK is configured to frequencies above 194 MHz.
#ifdef _LAUNCHXL_F28377S
    InitSysPll(XTAL_OSC,IMULT_40,FMULT_0,PLLCLK_BY_2); 		//PLLSYSCLK = (XTAL_OSC) * (IMULT + FMULT) / (PLLSYSCLKDIV)
#else
    InitSysPll(XTAL_OSC,IMULT_20,FMULT_0,PLLCLK_BY_2); 		//PLLSYSCLK = (XTAL_OSC) * (IMULT + FMULT) / (PLLSYSCLKDIV)
#endif

Step by step, I saw that the processor speed is being set to 100 MHz and not 200 MHz as imagined. So, after correct the ConfigCpuTimer function passing the correct, argument, did work.

Thanks anyway for readiness, but I'll leave a second question: How and where do I define that is _LAUNCHXL_F28377S, to set 200 MHz?

Vivek Singh, thanks a lot!!
Did work!