METHOD FOR MEASURING SELF REFRESH PERIOD OF SEMICONDUCTOR DEVICE AND ITS APPARATUS, ESPECIALLY INCLUDING AN EXTERNAL INPUT/OUTPUT PIN TO MEASURE SELF REFRESH PERIOD OF EACH BANK

摘要

PURPOSE: A method for measuring a self refresh period of a semiconductor device and its apparatus are provided to increase efficiency of testing normal operation of the memory device by measuring the self refresh period using an external input/output pin. CONSTITUTION: According to the method, the first pulse signal having the first period is generated y a self refresh command. A plurality of second pulse signals having a period larger than the first period are generated using a frequency multiplier(310) receiving the first pulse signal. One of the plurality of second pulse signals is selected. A pulse signal whose potential level varies at every one period of the selected second pulse signal is generated. And the generated pulse signal is transferred to the external through an input/output multiplexer(380) and an input/output pin(390).