Memory chip with buffer controlled based upon the last address cycle

A memory chip includes: a memory region; a chip determining unit configured to perform a chip determination, in writing operation, to determine whether or not the memory region is a writing target on the basis of an inputted address of writing destination, and to output a determination result of the chip determination; an address-cycle identifying unit configured to detect a final cycle of the address of writing destination, and to output a detection result at a timing before the output of the determination result; and a buffer controller configured to switch an input buffer from one state to another on the basis of the determination result, wherein the buffer controller keeps the input buffer in an active state irrespective of the determination result of the chip determination while the address-cycle identifying unit is outputting the detection result.