Hi, I am using AT89C51ED2 Micro controller, I have used "XDATA" for my buffer array, when the program is run , I am not able to get correct output, when the same array is used with "DATA" or "IDATA" as storage specifier it is working well... is there any problem in "XDATA" Rajesh
re 'internal external data' for most/all processors with internal xdata you must, at the beginning of setup.a51 set a SFR to enable the internal xram. Erik