C Program to Interface Keypad Using 8051

[CODE]#include <stdio.h> 		//Define I/O Functions
#include <reg51.h> 		//Define 8051 Registers
#define DATA P1 		//Define DATA to Port1
void Key_Scan(void); 	//KeyScan Function
void DelayMs(int); 		//DelayMs Function
sbit RS = P3^5; 		//Register Select
unsigned char R,C,ch;
unsigned int i=0;
unsigned char Key[4][4] = {'1','2','3','4', 
                           '5','6','7','8',
                           '9','0','A','B',
                           'C','D','E','F',
                           };
  // Main Function
void main()
{ 
while(1)
{
Key_Scan();
ch = Key[C][R]; 	//Assign Key value to ch;
SBUF=ch; 			//[C][R] denotes Column 
DelayMs(35); 		//and Row Value of Keypad
DelayMs(35);
}
}
  // Key Scan Funcion
void Key_Scan(void) 
{
unsigned int i = 0;
 					//Scanning for Row Value 
P2 = 0x0F; 			//Initialize Port2 to 0FH
while(P2 == 0x0F);
if(P2 == 0x0E) 		//Checking for Row0
R = 0;
else if(P2 == 0x0D) 	//Checking for Row1
R = 1;
else if(P2 == 0x0B) 	//Checking for Row2
R = 2;
else if(P2 == 0x07) 	//Checking for Row3
R = 3;
 					//Scanning for Column Value
P1 = 0x0F; 			//Initialize Port1 to 0FH
while(P2 == 0x0F);
if(P2 == 0x0E) 		//Checking for Column0
C = 0;
else if(P2 == 0x0D) 	//Checking for Column1
C = 1;
else if(P2 == 0x0B) 	//Checking for Column2
C = 2;
else if(P2 == 0x07) 	//Checking for Column3
C = 3;
DelayMs(50);
}
//Delay Function
void DelayMs(int k)
{
unsigned int a;
for(a=0;a<=k;a++);
}