| 摘要 |
PURPOSE:To provide two functions of page ang nibble modes by a semiconductor storage device by constituting the circuit that the mode at the next cycle is selected depending on the length of time when an external column address storobe signal (Ext.CAS) goes to an H. CONSTITUTION:When the time of the Ext.CAS going to the H is shorter than (t), data registers (DR1-DR4) and a column decoder CD keep the previous state, only a CAS1 is generated and shift registers (DS1-DS4) and an output buffer circuit OB are operated, then while the next Ext.CAS is activated as an L, the nibble mode is obtained. Further, when the Ext.CAS going to the H is longer than (t), the data registers (DR1-DR4), the column decoder CD and address buffer circuit or the like are all reset in addition to the shift registers (DS1- DS4) and the output buffer circuit OB and the page mode at the next cycle is attained. |
