TMS320F28377S: issue with the interrupt

Dear Experts,

I am trying to initialize timer and system initialisation. I had blinked a GPIO on and Off. However, I couldn't do accomplish the same task with the timer and interrupts and there are no errors though. Kindly see the issues in the code attached. In addition to that, I would like to know whether the program initalised the microcontroller at 200MHz.

#include "F28x_Project.h"

interrupt void timer_ovf_isr(void);

extern void InitSysCtrl(void);



void TimerInit();
void GpioInit();

int a =0;

void main(void)

{
     InitSysCtrl();
     TimerInit();
     GpioInit();
     DINT;
     InitPieCtrl();
     InitPieVectTable();
     EALLOW;


     EALLOW;
     PieVectTable.TIMER0_INT = &timer_ovf_isr;
     EDIS;

     PieCtrlRegs.PIEIER1.bit.INTx7 = 1;
     PieCtrlRegs.PIECTRL.bit.ENPIE = 1;

     IER |= 0x0001;

     EINT;          // Enable Global interrupt INTM
     ERTM;          // Enable Global realtime interrupt DBGM

     CpuTimer0Regs.TCR.bit.TSS = 0;
     while(1)
     {
             //idle
     }

}

void GpioInit(void)
{
     GpioCtrlRegs.GPAGMUX1.bit.GPIO13 = 0;
     GpioCtrlRegs.GPADIR.bit.GPIO13 = 1;
     GpioCtrlRegs.GPADIR.bit.GPIO12 = 1;
}
void TimerInit(void)
{
     CpuTimer0Regs.PRD.bit.LSW = 0x02FF;
     CpuTimer0Regs.PRD.bit.MSW = 0x002F;
     CpuTimer0Regs.TPR.bit.TDDR = 0x001F;
     CpuTimer0Regs.TCR.bit.TIE = 1;
     CpuTimer0Regs.TCR.bit.TRB = 0;
     CpuTimer0Regs.TCR.bit.TSS = 1;
     CpuTimer0Regs.TCR.bit.FREE = 0;
}

void timer_ovf_isr(void)
{

     GpioDataRegs.GPATOGGLE.bit.GPIO13 = 1;
     GpioDataRegs.GPATOGGLE.bit.GPIO12 = 1;
     CpuTimer0Regs.TCR.bit.TIF = 1;
     PieCtrlRegs.PIEIFR1.bit.INTx7 = 0;
     PieCtrlRegs.PIEACK.all = 0x0001;

}