currently i m using MSM62X42B RTC CHIP to interface with 8052 up. below is my </initial> programming to stop the clock and write in the 12 hr bit. The moment I execute pinWR = 0; the programme drop stop running. And I assign another pin rather then P3^6 and it does the same. I was wondering what could be the issue? #define THSR XBYTE[0X6F00] // the 'F' of J1 is assign to A9-A11 of the RTC sbit pinWR = P3^6; // this write is tie to WR of the RTC and ADC 0803 void main(void) { pinWR = 0; lcdPutStr("TIME:"); THSR = 0x00; // test = 0 THSR = 0x01; // rest = 1 to stop clock THSR = 0x01; // set 12 hr THSR = 0x03; // set stop bit to stop count THSR = 0x02; //start clock THSR = 0x02; //ser 12 again }