Hi, The interface DS12887 to MCU(I use 89c52) is all right.But I can't programe it with C51.My application is very simple.I just want to initiate and read the RTC.What can I do? Many thanks for any help!
Hi Vidarson, If you are interfacing ur DS12887 with 89C52,the things that come into consideration are 1.Make sure that the RTC is selected(Chip Select). 2.Configure the hardware A and B registers of the DS12887.You can use a pointer to access the registers(like a pointer that points to the base address of the RTC and u can increment it to point to the other locations of the RTC). 3.If u choose the BCD mode then care should be taken in the interpretation of the data that is being read from the RTC. eg.,Use the pointer like unsigned char xdata *RtcPtr; the routine for initialisation can be like this CS_RTC=0;//ChipSelect is Active low *(RtcPtr+10)=0x2F; *(RtcPtr+11)=0xC2;//make Set Bit =1 ///Initialize the date and time in BCD mode *(RtcPtr+11)=0x42;//Reset Set Bit to 0 CS_RTC=1; Regards, Rajesh.