What it is necessary to assign ROM & RAM in Project - Options - Target - External Memory if I want to use SRAM 256 KBit and Flash 8 MByte? What calculate these address?
This is a good question for this device. The PSB21493 is a very special C166 variant. Other devices have BUSCON/ADDRSEL registers that allow you to select address windows. Is this the same also here?
If so, you just need to enter the memory areas under Project - Options - Target as external memory.