WRITE-IN OPERATION MASKING METHOD FOR SYNCHRONOUS MEMORY AND DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To mask a write-in operation by the control of a mask information signal with respect to a device for masking the write-in operation of a synchronous memory. SOLUTION: A write-in mask information signal WRMSK- is applied to the central column selection circuit element 42 in a memory circuit. When the write-in mask information signal has contents that a present write-in operation is to be masked, the writing of data in memory cells 30 in the memory circuit is stopped by invalidating a column selection signal line with the column selection circuit element 42. When the write-in mask information signal has contents that a present write-in operation is not to be masked, data are written in proper memory cells in the memory circuit by the conventional method. When the write-in mask information signal has contents that the present write-in operation is to be masked, the column selection circuit element 42 invalidates a redundant column selection signal line.