发明公开
- 专利标题: Condition code prediction apparatus
- 专利标题(中): 条件码预测装置
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申请号: EP89100516.7申请日: 1989-01-13
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公开(公告)号: EP0328871A3公开(公告)日: 1991-07-03
- 发明人: Vassiliadis, Stamatis , Putrino, Michael , Huffman, Ann Elizabeth , Feal, Brice John , Pechanek, Gerald George
- 申请人: International Business Machines Corporation
- 申请人地址: Old Orchard Road Armonk, N.Y. 10504 US
- 专利权人: International Business Machines Corporation
- 当前专利权人: International Business Machines Corporation
- 当前专利权人地址: Old Orchard Road Armonk, N.Y. 10504 US
- 代理机构: Jost, Ottokarl, Dipl.-Ing.
- 优先权: US157500 19880217
- 主分类号: G06F7/02
- IPC分类号: G06F7/02 ; G06F7/50 ; G06F9/32
摘要:
The described embodiments of the present invention determine when two operands are equivalent directly from the operand without the use of an adder. In one embodiment, conditions for the sum being equal to zero are determined from half sum to carry and transmit operators derived from the input operands. These operands are used in some known types of adders and, thus may be provided from a parallel adder to the condition prediction circuitry. In another emobodiment, the equations for a carry-save-adder are modified to provide a circuit specifically designed for the determination of the condition when the sum of the operands is equal to zero. This sum is equal to zero circuit greatly reduces the gate delay and gate count thus allowing the central processing unit to determine the condition prior to the actual sum of two operands. This allows the CPU to react to the condition more quickly, thus increasing overall system speed.
公开/授权文献
- EP0328871A2 Condition code prediction apparatus 公开/授权日:1989-08-23
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