Help with Keypad 4x4 using RCM6500W

Hello,

I created a program to read a 4x4 keypad, but the output always 0xFF which means there is no button is pressed. Where is my fault location under this program? I'm so confused bcause,  

// all outputs add pull up to 3.3v with 4k7 resistor
// all inputs add series resistors 1k
//
// Keypad 4x4 with inputs (PB0-3) and outputs (PB4-7)
////////////////////////////////////////////											         //                            <-- INPUTS
//    1    2    3    Clear    <-- PB0
//    4    5    6    Up       <-- PB1
//    7	   8	9    Down     <-- PB2
//   Menu  0  Cancel Enter    <-- PB3
///////////////////////////////////////////
//   PB4   PB5  PB6   PB7     OUTPUTS

#use "rcm56xxw.lib"

unsigned char getKey(){
   unsigned char rowScan, readVal, writeVal, d;
   for(rowScan=0; rowScan<4; rowScan++){
      writeVal = ~(unsigned char)pow2(rowScan);
      WrPortI(PBDDR, &PBDDRShadow, writeVal);
      readVal = RdPortI(PBDDR);
      if(readVal != writeVal) break; // if button pressed, exit for
   }
   switch(readVal){
      // scan row 1     // OUTPUTS   <-- INPUTS
      case 0xEE:  	// 1110 1110 <-- 1111 1110
         return 1;
      case 0xDE:  	// 1101 1110 <-- 1111 1110
         return 2;
      case 0xBE:  	// 1011 1110 <-- 1111 1110
         return 3;
      case 0x7E:  	// 0111 1110 <-- 1111 1110 clear button
         return 0x0A;   

      // scan row 2
      case 0xED:  	// 1110 1101 <-- 1111 1101
         return 4;
      case 0xDD:  	// 1101 1101 <-- 1111 1101
         return 5;
      case 0xBD:  	// 1011 1101 <-- 1111 1101
         return 6;
      case 0x7D: 	// 0111 1101 <-- 1111 1101 up button
         return 0x0B;  

      // scan row 3
      case 0xEB:  	// 1110 1011 <-- 1111 1011
         return 7;
      case 0xDB:  	// 1101 1011 <-- 1111 1011
         return 8;
      case 0xBB:  	// 1011 1011 <-- 1111 1011
         return 9;
      case 0x7B:  	// 0111 1011 <-- 1111 1011 down button
         return 0x0C;  

      // scan row 4
      case 0xE7:  	// 1110 0111 <-- 1111 0111 menu button
         return 0x0E;   
      case 0xD7:  	// 1101 0111 <-- 1111 0111
         return 0;
      case 0xB7:  	// 1011 0111 <-- 1111 0111 cancel button
         return 0x0F;   
      case 0x77:  	// 0111 0111 <-- 1111 0111 enter button
         return 0x0D;   

      default:
          return 0xFF;	// no button is pressed
   }
}

void main(){
   brdInit();

  WrPortI(PBDDR, &PBDDRShadow, 0xFF);

   for(;;){
      costate{
          printf("%02X ", getKey());
      }
   }
}



Thank you,
DC








Thank you.