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8.2.7.3 Wallace Tree Multiplication
•
In effect, a “one’s
counter”: A, B, and
Cinputs and
encodes them on
SUMand CARRY
outputs.
• A 1-bit full adder
(FA) provides a 3:2
compression in the
number of bits.
A. Y. Wu
pp. 1
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Seven bits Wallace tree addition
A. Y. Wu
pp. 3
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Wallace Tree Multiplier
• MxNBooth-encoded multiplier (IEEE JSSC,
vol.1,no.2, June 1993)
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pp. 6
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A typical delay distribution of the
output of Wallace tree section
A. Y. Wu
pp. 7
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Extension
• 32-bits Wallace-tree multiplier has 9 adder delays
in the array
• Questions:
1. For a 64-bit multiplier, what is the minimum
adder delay?
Is there any way to reduce the delay by other
compression scheme?
2.
A. Y. Wu
pp. 8