Interfacing 8051 with HT1621 LCD Driver

#include <reg51.h>

//Interface with HT1621
sbit wr=P1^0;
sbit dt=P1^1;
sbit cs=P1^2;
sbit rd=P1^3;

int com_reg;          //Bits to be transferred is stored in com_reg

bit com_mode=0;       //Tells that commands are being transferred and not data

unsigned int mask=0x8000;

bit haha=0;

void delay (unsigned int j)
{
	unsigned int i=0;
	for(;i<j;i++);
}

void cs_pulse(void)
{
	cs=1;
	delay(1);	//For t(CS)
	cs=0;
}

void lcd_wr(void)
{
	//This will write data to HT1621

	rd=1;	//HT1621 clocks data out at falling edge of rd clock
	wr=1;	//Initializing rd and wr. rd will remain 1 forever.

	cs_pulse();

	delay(1);	//For t(su1)

	mask=0x8000;

	if(com_mode==0)
	{
		while(mask!=0x0004)
    	{
			wr=0;
			delay(1);	//For t(CLK)
			haha=com_reg & mask;
			dt=haha;
			delay(1);
			wr=1;
			delay(2);

			mask>>=1;
	    }
	}
	else if(com_mode==1)
	{
		while(mask!=0x0008)
    	{
			wr=0;
			delay(1);	//For t(CLK)
			haha=com_reg & mask;
			dt=haha;
			delay(1);
			wr=1;
			delay(2);
	  
			mask>>=1;
	    }		
	}

	delay(1);	//For t(h1)
	cs=1;
}

void main()
{
	//Initialization

	dt=0;
	
	delay(10000);
 
	com_mode=1;
	
	com_reg=0x8020;		//SYS EN

	lcd_wr();

	com_reg=0x8560;		//BIAS 1/3 with 4 commons
	lcd_wr();

	com_reg=0x8090;		//TIMER DIS
	lcd_wr();
							 
	com_reg=0x80A0;		//WDT DIS
	lcd_wr();

	com_reg=0x8280;		//XTAL 32K
	lcd_wr();

	com_reg=0x8060;		//LCD ON
	lcd_wr();
 	
	com_mode=0;

 	//Following code will put switch segments corresponding to addresses 1 and 2 of ht1621 on.
   com_reg=0xA0F8;
	lcd_wr();
	
	com_reg=0xA178;
	lcd_wr();
}