| 摘要 |
<p>The decoder circuit receives address signals A0 to A3 and selects one of 4x4 (=16) word lines W1 to W16 for driving a semiconductor memory device for example. The decoder circuit has a high level selection circuit HS which receives upper address signals A0 and A1 and produces four outputs E1 to E4, one of which is of a high level, while others are of a low level; and a low level selection circuit LS which receives lower address signals A2 and A3 and produces four outputs F1 to F4, one of which is of low level, while the others are of high level; and 4x4 (=16) coupling circuits CP1 to CP16 each of which corresponds to one of the word lines and each of which receives one output from the high level selection circuit HS and one output from the low level selection circuit LS. Each coupling circuit CP1 to CP16 selects a corresponding word line W1 to W16 only when the outputs of the high level selection circuit and the low level selection circuit which it is connected to receive are respectively and simultaneously high level and low level. </p> |
