Hi everyone., I am working on AT89c51ed2 micro-controller , I am facing problem with writing and reading the EEPROM data. I have followed all the procedures as stated in the data sheet, and the progarm is working fine when the power is ON., after switching OFF and ON of power supply I am not able to access the stroed data., I am accessing XDATA external to the chip with AXUR=0x02 disabling internal XRAM data access, and restoring back the actual AXUR=0x01 conditon. when I again access the data after Powering ON I am getting zero,and not the actual data. I am surpried how it can only work in power ON mode as EEPROM should access back the data stored. Is there any problem with XDATA as it used to access External data , internal XDATA and EEPROM also. If any one has a solution to this problem please send me suggestion or small peice of code and help me. Waiting for a Positive reply., Thanking you, Rajesh