SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE:To prevent the operation in a test mode after shipment by fusing a fuse after performing the test before shipment. CONSTITUTION:When the test before shipment of a SRAM is required, a pulse signal PL having the pulse width wider than a predetermined time length is given through a terminal 62. A pulse width detecting circuit 80 detects the pulse width of the supplied pulse signal and outputs a holding signal HD. A holding circuit 90 for a test mode signal holds a test mode request signal TM' given from outside responding to the holding signal HD. After the termination of the test before shipment, the pulse width detecting circuit 80 is disabled by fusing a fuse 71.