Description
Purpose: In this project you are asked to define and test a Half Adder
Objectives:
- Continue to get familiar with EDAPlayground
- Start to learn HDL (Verilog) basics
- To understand binary addition
Step 1: create module on the right panel
The Half Adder is a digital building block with 2 inputs (A, B) and 2 outputs (S, Cout). The Half Adder logic must be modeled next. The circuit below shows the Half Adder logic circuit and the equivalent boolean equations:
|
S = A xor B
Cout = A and B |
Binary Operator Symbols in Verilog
| ~ | NOT |
| *, /, % | mult, div, mod |
| +, – | add,sub |
| <<, >> | shift |
| <<<, >>> | arithmetic shift |
| <, <=, >, >= | comparison |
| ==, != | equal, not equal |
| &, ~& | AND, NAND |
| ^, ~^ | XOR, XNOR |
| |, ~| | OR, NOR |
| ?: | ternary operator |
This completes the verilog module definition of the half adder. Next it must be tested to ensure it works correctly.
Step 2: Create a Half Adder Verilog Test Fixture. To test a module for correct functionality, a set of inputs will be provided to produce an expected set of outputs. A Verilog Testbench is used to test a Verilog source module.
Create the Half Adder test script. To test a module for correct functionality, a set of inputs will be provided to produce an expected set of outputs. For simple modules like the half adder a truth table is used to show the outputs that can be expected from a set of inputs.
The Cout output column shows that Cout equals 1 only when A equals 1 and B equals 1.
The S output column shows that S equals 1 when the value of A is not equal to the value of B.
Simulation results are shown as waveforms.
Finally, upload report to the project Dropbox in beachboard (refer to EDAPlayground Tutorial for report guidance)!