Memory device which can change control by chip select signal

摘要

A memory device has an address terminal for inputting a plural bits of address signal, and a chip select terminal for inputting an external chip select signal, and an access mode controlling circuit which can switch a first control mode for controlling enable/disable of memory device according to plural external chip select signals and a predetermined address signal in the address signal to be input, and a second control mode for controlling the enable/disable according to a single external chip select signal. If the memory device is larger than a first memory area which can be controlled by a single chip select signal, the memory device can be directly connected to the memory control unit by setting the access mode control circuit to the first control mode. If the memory device is less than the first memory area, the access mode control circuit is set to the second control mode.