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:
  • txt
  • txt
• According to content in _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 _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.
• _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 1 0
• 0 0 1

Example:

• Suppose that _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

• _txt has the following content:
  • 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 _txt.
• Each line in _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:
  • 0 0 0
  • 0 0 1
  • 0 0 0

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
a	b	out
0	0	0
0	1	1
1	0	1
1	1	1

• OR
• 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