| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To shorten test time in a data holding time test of a dynamic ROM using no test circuit or a simple test circuit. <P>SOLUTION: While an address pre-charge signal AP is an H level, a data holding capacitor 300 is charged by a ROM pre-charge signal RP. Then, all output of AND gates 100-102 for address decoder are made an L level by inputting address signals (A1, A2)=(1, 1) showing an address that a ROM cell to be accessed is not mounted, and all ROM cells 220-222 are made OFF. Next, the ROM pre-charge signal RP is made an L level, and the data holding time of the dynamic ROM is tested by confirming that a holding capacitor potential Vc0 is an H level. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
