Implementing a 4 bit Counter using an 8051 and Interfacing it to an LCD 1.0

The program will be used to control a simple 4-bit up-down counter, capable of counting from 0 to 15. At each step the count should be displayed in decimal format on the LCD.

he 4 bit counter has the following functionality:
The counter has the following input pins :
a. Reset : when high resets the counter dataout to ``0000''
b. Updown : decides whether the counter counts up or down.
c. Load : makes the counter count from the 4 bit input Datain
d. Datain : which is a 4 bit input count
The counter has a 4 bit Dataout to reflect the count.
The count has to be sent to the LCD and displayed in decimal format.

Code (Text):

1. #pragma SMALL DB OE
2. #include
3. #include "io.h"
4.  
5. /* P0, P1, P2 and P3 are predefined port names and are bit addressable */
6.  
7. sbit reset = P0^4; /* bit 4 of Port 0 */
8. sbit up_down = P0^5;
9. sbit load = P0^6;
10. sbit Start_LCD = P0^7; /* bit 7 of Port 3 */
11.  
12. /* Delay function */
13. void delay() {
14.  
15.         int i, j;
16.  
17.         for(i=0; i<1000; i++)
18.                 for(j=0; j<100; j++)
19.                         i = i + 0;
20. }
21.  
22. /* Function to output the decimal value of the count on the LCD */
23. void PrintInt(unsigned char i) {
24.       char ch[4];
25.  
26.       /* Write code to convert the count to a string value and use the
27.           PrintString function provided in io.c */
28.  
29.         PrintString(ch);
30. }
31.  
32. void main(void) {
33.  
34.         unsigned char count = 0;
35.  
36.         InitIO();  /* Initialize the LCD */
37.         while (1) {
38.                 if (Start_LCD == 1) {
39.                         ClearScreen();
40.                         PrintString("Ready...");
41.                         delay();
42.                 }
43.                 else if (reset == 1) {
44.  
45.                         /* Output 0 on the LCD */
46.  
47.                 }
48.                 else if (load == 1) {
49.  
50.                       /* Output the current value of Datain on the LCD */
51.  
52.                 }
53.                 else {
54.                         /* Check the Up/Down pin for 1 or 0 count up or down
55.                           accordingly. Display each value on the LCD */
56.               }
57.       }
58. }