Configuring adc of tms470r1b1m controller

im using #-Link-Snipped-# controller for my project.i need an ADC for processing the analog input.
in iar workbench,i had configured the registers but the code is not working.
code is given below.plz give me a solution..........

#include <intrinsics.h>
#include "iotms470r1b1m.h"
#include "tms470r1b1m_bit_definitions.h"
#include <stdio.h>

void main(void)
{
  int result;
  PCR = CLKDIV_3;                         // ICLK = SYSCLK / 3
  GCR = ZPLL_CLK_DIV_PRE_1;               // SYSCLK = 8 x fOSC
  PCR = PENABLE;                         // Enable peripherals


  PLR = (PLOC3&0);                      //peripheral selects, The peripheral is internal
  PPROT = (PPROT3&0);             // peripheral selects,The peripheral is accessible in all modes
  CLKCNTL = 0x00000020;
  

  ADCR1 = PS_8;                          // ADCLK prescaler = 8
  ADCR1 = COS; 
  ADCR2 |= G1_MODE;                       // Continuous Conversion
  ADSR =0x0000;                    // Clears flag 
  ADEISR=0x0000;    // event disabled
  ADISR1 = 0x0020;   // Convert group 1 = channel 5
  ADISR2 = 0x0000;  //grp2 disabled
  ADCALR = 0x000;    //no Calibration
  ADSAMPEV = SEN;                        // ADCSAMP1 controls SW
  ADSAMP1 = 62;                           // SW = 62+2
  ADCR1 = ADC_EN;                        // Enable ADC
  
  
  for (;;)
  {
    
   while (!GP1_END);             // Wait for conversion to complete
   {
   }
    result = ADDR5;
    printf("RESULT is %d",result);
    ADSR =0x0000;  
  
  }
}

when this code is executed in iar workbench, the ADC is not activated nor does it sets GP1_END bit to indicate the completion signal.hence the code never exits from the while loop.here input is given to channel 5.i couldn't identify the problem..
plz give me a solution.............