| 摘要 |
PURPOSE: A circuit for repairing the Y-address of a memory is provided which repairs a poor chip into a half density chip using a memory region configured of only bit lines having no poor cell when repairing using a redundancy cell is impossible to perform. CONSTITUTION: A circuit for repairing the Y-address of a memory includes a memory array(100), a Y-address buffer(110), a half density chip controller(120), a Y pre-decoder(130), a Y-decoder(140), a comparison and fuse unit(150) and a Y redundancy decoder(160). The memory array is constructed of multiple cell storing data and a sense amplifier for sensing the data. The Y-address buffer receives a column address to buffer the column address. The half density chip controller generates address information about repairing of a half density chip and a region used for repairing the half density in a memory region corresponding to a signal obtained by decoding upper 3-bit X-address according as a fuse is cut or not. The Y pre-decoder selectively pre-decodes h column address output from the Y-address buffer according to the memory region address information. The Y-decoder decodes the Y-address pre-decoded by the Y pre-decoder to enable the sense amplifier connected to a corresponding bit line pair. The comparison and fuse unit judges if a bit line is failed to cut a fuse corresponding to a poor address. The Y redundancy decoder disables a bit line corresponding to a poor address and enables a redundancy bit line.
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