发明名称 |
CARRY LOOKAHEAD ADDER FOR DIFFERENT DATA TYPES |
摘要 |
An adder is proposed which has circuitry for calculating the sum of or difference between pairs of unpacked binary numbers having 2<n> bits or packed binary numbers having 2<n-m> bits where m < n. The adder has 2<m> sub-adders, with each sub-adder partition including a plurality of columns and a plurality of rows of cells. The columns of cells each have an input cell in the lowermost row for receiving bits of each of the pairs of numbers. Each sub-adder above the lowest significance sub-adder has a lowest significance column input cell arranged to receive a third input bit. The cells in the remaining rows of the or each sub-adder above the lowest significance sub-adder are arranged to prevent the carry-over of a carry bit from the most significant column of the preceding sub-adder being introduced into the sub-adder, depending on whether the third input bit is zero or one.
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申请公布号 |
WO0246910(A1) |
申请公布日期 |
2002.06.13 |
申请号 |
WO2001GB05358 |
申请日期 |
2001.12.04 |
申请人 |
UNIVERSITY COLLEGE CARDIFF CONSULTANTS LIMITED;BURGESS, NEIL |
发明人 |
BURGESS, NEIL |
分类号 |
G06F7/50;G06F7/508;(IPC1-7):G06F7/50 |
主分类号 |
G06F7/50 |
代理机构 |
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地址 |
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