Hello all, I have a very complicated question 4 U. In my target board I use the T89C51RD2 micro and also two types of external memory devices; SRAM 32KB and parallel EEPROM 8KB. My code runs from micro's internal memory and from SRAM. The EEPROM is for data storage. All my software is based on Keil's RTX51-Full operating system. One of the project requirements is to save some data such as date and time for cases such as hw/sw reset, power down and etc. At this moment I only backup the data when I receive software reset. In this case I get the followings: 1. Data is saved also in hardware reset, despite the fact that I didn't handle this case. 2. Despite that data is saved at hardware reset, power off/on mode doesn't save the data. 3. If I saved the data (by entering to software reset) and then torn off and on target's power supply, data NOT saved on external EEPROM. 4. If I enter clock data (11:11:00 for example) to system (run in SRAM) but NOT save it in EEPROM and I press the hardware reset switch, system starts with current data value (11:11:10). Can someone help me with that???