Semiconductor memory device having shifting circuit connected between data bus lines and data buffer circuits for changing connections therebetween

摘要

A semiconductor memory device has a plurality of memory cell sub- arrays selectively used as a data storage for prohibiting a defective memory cell sub-array from a data access, and a shifting circuit couples the available memory cell sub-arrays to input and output data buffer circuits higher in a priority than another input and output data buffer circuit regardless of the location of the defective memory cell sub-array in the plurality of memory cell sub-arrays so as to share a printed circuit board between the semiconductor memory devices with the partially available memory cell sub-arrays.