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# Method of Generating Thermometer Code Output for Compare Operation Using Special Decoder

IP.com Disclosure Number: IPCOM000249539D
Publication Date: 2017-Mar-02
Document File: 2 page(s) / 18K

## Publishing Venue

The IP.com Prior Art Database

## Abstract

Described is a method of generating thermometer code output for compare operation using special decoder.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 74% of the total text.

1

Method of Generating Thermometer Code Output for Compare Operation Using Special Decoder

This invention performs a 2^n compares between a n-bit binary input data value against 2^n

possible binary indexes and produces a 2^n-bit thermometer code that has values of 1 for all

indexes that are less than the n-bit binary input data value. The current invention uses a special

n-bit decoder that uses the n-bit binary input data value to produce a 2^n-bit output such that the

decoded value is 1 if the n-bit binary input data value is greater then the index of the

corresponding 2^n-bit decoder value.

Instead of implementing 2^n comparators, a n-bit special decoder circuit is implemented.

For each of the 2^n outputs of the decoder, the logic is such that the value of the output is

dependent upon the current index is strictly less than the n-bit input. So this is a circuit that is

kind of a decoder and comparator combined together to perform a special function. The circuit is

faster, smaller, and uses less power than prior art. The following logic truth table summarizes

the circuit for n=5-bits

Input = In<4:0>

Output=LT<31:0>

In<4> In<3> In<2> In<1> In<0> LT<0> LT<1> LT<2> LT<3> LT<4> ... LT<31>

0 0 0 0 0 0 0 0 0 0 ... 0

0 0 0 0 1 1 0 0 0 0 ... 0

0 0 0 1 0 1 1 0 0 0 ... 0

0 0 0 1 1 1 1 1 0 0 ... 0

0 0 1 0 0 1 1 1 1 0 ... 0

0 0 1 0 1 1 1 1 1 1 ... 0

0 0 1 1 0 1 1 1 1 1 ... 0

0 0 1 1 1 1 1 1 1 1 ... 0

0 1 0 0 0 1 1 1 1 1 ... 0

0 1 0 0 1 1 1 1 1 1 ... 0

0 1 0 1 0 1 1 1 1 1 ... 0

0 1 0 1...