I need to store variables in nonvolitile memory using the 8051. I previously thought that this was impossible and my goal could only be accomplished through the use of an external EEPROM device; however, I have been told that it may be possible to use XDATA Banking to put 'C' variables in the EEPROM. Is this true? and if so, how do I go about doing it? Suggestions are greatly appreciated.
"That could only work if you have EEPROM that can be written to by ordinary MOVX instructions." No, that's not true. I have it on reliable authority (Jon Ward said) that the C51's so-called "XDATA-banking" support can be used to do this: http://www.8052.com/forum/read.phtml?id=24473 I've never done it myself, so the OP will just have to follow Dan's advice and look-up the examples... See also: http://www.keil.com/support/docs/2103.htm