| 摘要 |
PURPOSE:To improve the efficiency of screening by supplying a screening test mode signal and a cas-before-ras(CBR) mode designating signal from outside and performing a screening operation. CONSTITUTION:This device is provided with a 1st terminal 24 dedicated to a screening test and a 2nd terminal dedicated to the screening test and the screening test mode signal BI and CBR mode signal CBR are supplied to the terminals 24 and 25 from outside. Then once the states of the signals BI and CBR are detected, the mode setting circuit incorporated in a refreshing operation control circuit 27 outputs a signal for setting a screening test mode stand-by state or read mode. Therefore, stress can be applied to the word lines, bit lines, and all columns of a memory cell array 15 only by providing the two dedicated terminals, and the screening efficiency can be improved more. |
