The DS1642 is an RTC + NVRAM The information is in centain memory locations in bcd format. Ok , so i made a simple program to display the minutes :
#include <reg51.h%gt; xdata minutes _at_ 0x07FA; //this is the memory location containing minutes xdata control _at_ 0x07F8; //this is the control reg void main() { while(1) { control = 0x40; //set the read bit putchar(13);putchar(10);putchar('m');putchar('='); //eye candy punchar(minutes); control = 0x00; //reset the read bit delay(100); } }
"What is the data type here?" In 'C', eveything is an int unless otherwise specified.