| 摘要 |
PURPOSE: To obtain a speedy and relatively small high base carry look ahead tree by allowing each of plural tree nodes to include a carry chain or the deformation, and/or an HAND gate chain or the deformation. CONSTITUTION: Three different types of blocks are arrayed in three levels. The first level includes 15 corrected carry chain blocks 74-102, and a carry chain block 104 corrected for carry-in, and block propagation and generation is generated for four input positions. The second level includes four Manchester carry chain nodes 106-112, and the block propagation and generation is generated from the four of the first level. Therefore, the second level provides information related with 4×4 or 16 bit blocks. The third level includes two Manchester carry chain nodes 114 and 116, and provides block information related with the four or 4×(4×4) or 64 hits of the blocks of the second level.
|
