Programming Assignment 4 Solution

Description




This is an individual assignment. Please do not collaborate



If you think that this document does not clearly describes the assignment, ask questions before its too late.



This assignment is about implementing and testing classes for a logic circuit simulator.




Your program reads two files:



– circuit.txt




– input.txt




According to content in circuit.txt, the program dynamically creates necessary objects for a logic circuit and evaluates the states listed in input.txt.



Your program prints the output to stdout. Each line in input.txt is a state. For each state, there should be a line of output printed.



circuit.txt




Each line starts with a keyword. Possible keywords:



INPUT




OUTPUT




AND




OR




NOT




FLIPFLOP




DECODER




The first line specifies input labels. Labels are separated by spaces. Example:



INPUT a input2 c3 k




Here there are 4 inputs are defined. Each has an identifier. a, input2, c3, k.



The second line specifies output labels. Labels are separated by spaces. Example:



OUTPUT d1 d2 d3 d4




Here there are 4 outputs are defined. Each has an identifier. d1, d2, d3, d4.



AND keyword specifies that there is an and gate defined. AND keyword follows the identifier for its output and two other identifiers for the inputs. Example:



AND gate_A c3 another_id




Here the and gate has an output identified by the string gate_A. Its inputs are identified c3 and another_id. These identifiers can be input identifiers or identifiers for other gates.



OR keyword specifies that there is an or gate defined. OR keyword follows the identifier for its output and two other identifiers for the inputs. Example:



OR gate_B ck id3




Here the or gate has an output identified by the string gate_B. Its inputs are identified ck and id3. These identifiers can be input identifiers or identifiers for other gates.






1
NOT keyword specifies that there is a not gate defined. NOT keyword follows the identifier for its output and one other identifier for its input. Example:



NOT gate_C c5




Here the not gate has an output identified by the string gate_C. It has only one input an it is identified by the string c5.



FLIPFLOP keyword specifies that there is a flip-flop gate defined. FLIPFLOP keyword follows the identifier for its output and one other identifier for its input. Example:



FLIPFLOP gate_F c6




Here the flip-flop gate has an output identified by the string gate_F. Its input is identified by c6.



DECODER keyword specifies that there is a decoder gate defined. DECODER keyword follows the identifiers for its outputs(o1, o2, o3, o4) and identifiers for its inputs(a1, a2). Example:



DECODER d1 d2 d3 d4 g1 another_identifier




Here the decoder gate has outputs identified by strings o1, o2, o3, o4. Its inputs are identified by g1 and another_identifier.



input.txt




Each line is a list of 1 and 0. Example:



1 0 1 1




0 1 1 1




0 0 1 0




1 0 0 1




Example:




Suppose that circuit.txt is has the following content:



INPUT a b c d




OUTPUT d1 d2 d3 d4




AND and1 a b




OR or1 and1 c




NOT n1 d




FLIPFLOP f1 n1




AND a2 or1 f1




DECODER d1 d2 d3 d4 a2 f1




input.txt has the following content:



1 1 0 1




1 0 1 0




1 1 1 0




Assume that initially former-out of any FLIPFLOP is 0.



Any FLIPFLOPs should preserve the state throughout the evaluation of the whole input.txt.



Each line in input.txt is assigned to identifiers a, b, c, d, defined in circuit.txt. According to the truth tables, outputs of gates are calculated.



For the input.txt given, the output of your program should be:



1 0 0 0




0 0 0 1




1 0 0 0







2
and



b


gate






















and












and1
or




or1






















gate












gate






c


















flip
f1








a2




















flop
















d








not
n1












decoder


d1








gate


















d3d2
































































































d4













































Figure 1: Example Logic Circuit




Remarks




Each identifier is unique. You can assume that their length is limited to 15 characters. You can use std::string.
There won’t be any errors in the files.



You have to use dynamic memory allocation and C++ classes.



You have use inheritance and polymorphism. Find a class hierarchy and try to use abstraction.



You are not allowed to used std::vectors.



You cannot use components which are not covered in class. (such as templates etc..)



In order to learn about file I/O operations, you can go through the related book chapter(not covered in class). Or you can read the section presented in assignment 3.



Turn in:




Source code of a complete C++ program and a suitable makefile. You should use c++11 standard. Your code will be tested in a linux-gcc environment.
A script will be used in order to check the correctness of your results. So, be careful not to violate the expected output format.



Provide comments unless you are not interested in partial credit. (If I cannot easily understand your design, you may loose points.)



You cannot get full credit if your implementation contradicts with the statements in this document.








Truth Tables:




AND



a
b
out






0
0
0
0
1
0
1
0
0
1
1
1









OR



a
b
out






0
0
0
0
1
1
1
0
1
1
1
1









NOT






a out







0 1




1 0







FLIPFLOP



a
former_out
out






0
0
0
0
1
1
1
0
1
1
1
0









DECODER



a1
a2
d1
d2
d3
d4












0
0
1
0
0
0
0
1
0
1
0
0
1
0
0
0
1
0
1
1
0
0
0
1































































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