622 ECE2204 4x4 Array Multiplier
622 : ECE2204 4x4 Array Multiplier
- Author: Jason Brandon
- Description: 4x4 Structural Array Multiplier
- GitHub repository
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How it works
The Verilog code is for a 4x4 array multiplier that takes two 4-bit numbers, m and q, and produces an 8-bit result. It starts by splitting an 8-bit input into two parts: the upper 4 bits represent m and the lower 4 bits represent q. To calculate the product, the code computes partial products using bitwise AND operations. Each partial product corresponds to a bit of q, and there are four arrays created for these. After that, the code sums these partial products with a series of full adders. Each full adder takes inputs from the previous stage and the next bits of the partial products, managing carries as needed. The final sum is stored in an 8-bit variable p, which is then sent to the output. The full adder used in this process helps calculate the sum and carry-out from two inputs and a carry-in. This method of breaking down the multiplication into partial products and adding them up demonstrates a clear and structured approach to implementing a basic multiplier in hardware.
How to test it
To test the Verilog program for the 4x4 array multiplier, the user would create a testbench, which is a separate module designed to evaluate how the multiplier functions. They would begin by setting up a variety of 4-bit input values, including simple cases such as all zeros and all ones, as well as some random combinations. This approach helps ensure that the multiplier can handle different scenarios correctly. Next, the user would run the testbench with these inputs and check the outputs against the expected results of the multiplication. Since the multiplication of two 4-bit numbers can yield an 8-bit result, they would calculate the expected outputs manually or use a calculator for verification. To facilitate this process, the user would add print statements to display the outputs on the console. If any outputs do not match the expected values, they would review the code to identify and correct any mistakes. By systematically testing various inputs and confirming the results, the user can ensure that the multiplier operates as intended.
External hardware
N/A
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | q[0] | p[0] | |
| 1 | q[1] | p[1] | |
| 2 | q[2] | p[2] | |
| 3 | q[3] | p[3] | |
| 4 | m[0] | p[4] | |
| 5 | m[1] | p[5] | |
| 6 | m[2] | p[6] | |
| 7 | m[3] | p[7] |