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Bcd to Excess-3 Code Convertor

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Bcd to Excess-3 Code Convertor

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  • July 30, 2013
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Implementation of BCD To Excess-3 Code Convertor
Ritu Ashok Gupta RAIT Navi-Mumbai rg140593@gmail. com Gayatri Katkar RAIT Navi-Mumbai gayatrigkatkar@g mail.com Snehal Kadam RAIT Navi-Mumbai snehalkadam2512 92@gmail.com Mrs. S.N. Ghate RAIT Navi-Mumbai snghate23@gmail. com

ABSTRACT
The primary advantage of XS-3 coding over BCD coding is that a decimal number can be nines' complemented (for subtraction) as easily as a binary number can be ones' complemented ; just invert all bits. In addition, when the sum of two XS-3 digits is greater than 9, the carry bit of a four bit adder will be set high. This works because, when adding two numbers that are greater or equal to zero, an "excess" value of six results in the sum. Since a four bit integer can only hold values 0 to 15, an excess of six means that any sum over nine will overflow. A code converter is a circuit that makes the two systems compatible even though each uses a different binary code. Our project is to convert a user entered BCD number into Excess-3 using 4:1 MUX. We chose to use multiplexer so as to simplify the circuit and reduce the use of more number of IC’s.

channel is displayed on your screen. Similarly, you select a radio station to listen to, and it plays on your radio. An n-1 MUX consists of the following: Data inputs: n Control inputs: ceil (log2 n) Outputs: 1 Where ceil is the ceiling function ceil(x) = n for the smallest integer where n >= x. Given n possible choices for inputs, you need log2 n bits to select it (technically, you need the ceiling of this; just in case n is not a power of 2). For example, if you have 16 possible inputs, you need 4 bits to specify one of 16 values. If you have, say, 12 possible inputs, you still need 4 bits, even though some of the 4 bit patterns may not correspond to any of the 12 choices. 4:1 MUX In electronics, a multiplexer (or MUX) is a device that selects one of several analog or digital input signals and forwards the selected input into a single...