Modify genetic algorithm code that designs a 6-bit parity checker to design a 2-bit adder. Graduate students need to make the GA design a three-bit adder without allowing the genetic algorithm to use XOR gates. A 2-bit adder adds 2, 2-bit inputs and produces a 3-bit output. A 3-bit adder adds two, 3-bit numbers and produces a 4-bit output.

• You will need to change code in app.c and perhaps some of the .h files.

• You will need to change appinfile (which specifies the problem to be solved by the GA) and perhaps infile (which specifies GA parameters).

• You will probably need to read all the code to get an understanding of what it does and how.

• You may write your own GA and evaluator (simulator) for combinational logic circuits.

Resources

• Tarred, gzipped GA code applied to the design of a 6-bit parity checker.......|...... Here is the untarred directory .
• Default CONSTs used in code
• The evaluator/simulator
• The genetic algorithm input file
• The application (parity checker) input file

The genetic algorithm can be run with a number of options. bin/run.sh is a shell script that uses three of the available options.

• -i infile : The -i option can be used to specify a file of ga parameters
• -a appinfile : The -a option can be used to specify the name of a file from which to read application specific data. In the parity problem, this is 1) Number of input bits, 2) Number of rows, and 3) the number of columns of the gate array that holds the circuit.
• -s 0.9374 : The -s option specifies a random seed between 0 and 1 for the ga to use.
• -o outfilename : The -o option specifies the base name of an output file. Files outfilename, outfilename.fit, outfilename.pheno will be produced. For the parity checker, outfilename.pheno will be blank.

Turning it in Please turn in a graph of fitness versus number of generations for the run of the GA that produced a correct circuit. Also turn in the binary representation of the circuit as well as a corresponding circuit diagram. Turn in a diff listing of files that you changed (%diff file1 file2 lists all differences between file1 and file2). Finally, answer the question: How does your circuit work?