I am using the DS1643 which contain both non voliate ram and a RTC. also, in my project, i use the timer 1 interrupt to counter the machine operation time: unsigned char second, min, hour; i use XBYTE[0x1ffe0]=second; XBYTE[0x1ffe1]=min; XBYTE[0x1ffe2]=hour; then i have a function to recall the NVram data to the counter variavle. it is not problem for the reset the system, and all data can be keep. however, when i remove the power supply, all data are going wrong. How can i solve this problem? any programming skills needed for using NVRAM? Pls help!!!!!!!!!!!!!!!! many thx!!!!!!!!!!!!!!
I am not familiar with your device, but many RTC type chips which have an internal battery are shipped with the battery disabled, and you have to set an obscure bit in a control register to enable the battery.