I have to use 512K code and 256k xdata as 8 bank,code bank:0x00000~0x00fffff,...,0x070000~0x07ffff, xdata bank: 0x000000~0x007ffff,...,0x070000~0x077fff. keil c docment imply that the code bank and xdata bank must use the same hardware.but code bank have the commom bank ,and the routines at the common bank must use some xdata ram,but not have the common xdata bank . can i define the variable as 'far'type? if the routine(commonbank) run at bank 3,the variable(xdata) at bank1,the keil c51 can switch it and deal with it?!thanks!