Objective
In this lab, we will build a half-adder, a full-adder and a
4-bit adder from the full-adder. We will also build a
gray-code encoder & decoder.
Part 1. Ripple Adder.
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i.
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Design a full-adder starting with a half-adder. Briefly describe the design
(how a 1/2 adder works and how putting together two 1/2 adders will make up
a full-adder, mention the sum & carry in relation to the inputs).
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ii.
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Use the enclosed full adder tutorial to build a full adder using xilinx program.
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iii.
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Build a 4-bit adder using xilinx & simulate the 4-bit adder using xilinx.
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Part 2. Construction of a Combinational Logic for the Gray-code ENCODER
Design a combinational logic circuit that converts three-bit binary code counter
to three-bit gray-code counter (Gray Code ENCODER)
abc wxy
000 000
001 001
010 011
011 010
100 110
101 111
110 101
111 100
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i.
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Briefly describe what a gray-code encoder is.
Describe what is a hazard and how gray-code prevents hazards.
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ii.
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Design the encoder circuit (K-map, Algebraic expression)
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iii.
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Build the gray-code encoder circuit & simulate the gray-code encoder using xilinx.
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Part 3. Construction of a Combinational Logic for the Gray-code DECODER
wxy efg
000 000
001 001
011 010
010 011
110 100
111 101
101 110
100 111
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i.
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Briefly describe what a gray-code decoder is.
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ii.
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Design the encoder circuit (K-map, Algebraic expression, etc.)
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iii.
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Build the gray-code dncoder circuit & simulate the gray-code decoder using xilinx.
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Part 4. Multiplexer
Build a circuit that translate a 8-bit parallel data to a serial output. Use only 2:1 Muxes.
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i.
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Define the specification for this 8-bit parallel to serial circuit.
(input, output & their relationship)
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ii.
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Briefly describe how you design this circuit.
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iii.
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Build and simulate the circuit using xilinx and demonstrate the
simulation result.
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Report
Title page:
- Names of students and due date.
- Title of the lab and objective.
- A brief description of each person's contribution.
Content:
- Part 1 i, ii, iii (include design & simulation for 1/2, full, and 4-bit adder).
- Part 2 i, ii, iii
- Part 3 i, ii, iii
- Part 4 i, ii, iii
- Attach the lab assignment at the end of the lab report.
- Hint on a good report: Be descriptive but not wordy. Good example would be:
Part 2.ii: The following is the design for the gray-code encoder.
Think of yourself as the grader but doesn't have the hand out. The grader
should know what you did in the lab without looking at the hand out.
**Also, remember to label the simulation result (timing diagram) with 0's & 1's
and short descriptions of what test-cases you have tested.
Grading
90% will based on the completeness and correctness of the report. 10% will
based on the neatness, organization, and following instruction of the report
format.
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