MEMORY CONTROLLER

PURPOSE:To easily constitute a memory device which is most suitable for storing data of a desired bit length by using semiconductor memories different in bit constitution by changing a set point value or the like to an offset setting means. CONSTITUTION:When an external address (address 20000) is fetched into comparators CMP1-CMP9 in synchronism with the fall of an address strobe signal AS supplied from a CPU board, it is compared with addresses which are set in address registers ADR1-ADR9. The outputs CE1-CE5 of coincident comparators CM1-CM5 are changed to low levels. The memories MEM1-MEM4, of four pieces X eight constitution, are simultaneously accessed and the address to which an offset value is added is supplied to the memory MEM5. The addresses 20000, 120000, 220000 and 320000 are sequentially accessed. Thus, data of total 36 bits are outputted to a data bus 24.