Help with Keypad 4x4 using RCM5600W

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?

// 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