Why memory blocks are needed in Verilog - See It in Action

Why Memory Blocks Are Needed in Verilog

📖 Scenario: Imagine you are designing a simple digital system that needs to remember some values over time, like a small notebook that stores notes. In hardware design, this is done using memory blocks.

🎯 Goal: You will create a small Verilog module that uses a memory block to store and retrieve data. This will help you understand why memory blocks are needed in hardware design.

📋 What You'll Learn

Create a memory array to store 8-bit values

Add an address input to select which memory location to read or write

Use a write enable signal to control when data is stored

Read data from the memory based on the address

Display the stored data

💡 Why This Matters

🌍 Real World

Memory blocks are used in digital devices like computers, phones, and embedded systems to store data and instructions.

💼 Career

Understanding memory blocks is essential for hardware engineers and FPGA designers who build efficient digital circuits.

1

Create a memory array

Create a memory array called mem that can store 16 elements of 8 bits each.

Verilog

// Declare a memory array called mem with 16 elements of 8 bits each
// Your code here

Need a hint?

Use reg [7:0] mem [0:15]; to declare a memory array with 16 elements of 8 bits.

2

Add address and control signals

Add inputs called addr (4 bits), data_in (8 bits), and write_enable (1 bit) to the module.

Verilog

reg [7:0] mem [0:15];
// Add inputs addr (4 bits), data_in (8 bits), and write_enable (1 bit)
// Your code here

Need a hint?

Use input [3:0] addr; for address, input [7:0] data_in; for data input, and input write_enable; for write control.

3

Write data to memory

Write an always block that writes data_in to mem[addr] when write_enable is high.

Verilog

reg [7:0] mem [0:15];
input [3:0] addr;
input [7:0] data_in;
input write_enable;

// Add always block to write data_in to mem[addr] when write_enable is high
// Your code here

Need a hint?

Use an always @(posedge write_enable) block to write data_in to mem[addr] on the rising edge of write_enable.

4

Read and display stored data

Add an output data_out (8 bits) and assign it to the value stored in mem[addr]. Then print data_out.

Verilog

reg [7:0] mem [0:15];
input [3:0] addr;
input [7:0] data_in;
input write_enable;

always @(posedge write_enable) begin
    mem[addr] <= data_in;
end

// Add output data_out and assign mem[addr] to it
// Print data_out
// Your code here

Need a hint?

Use output [7:0] data_out; and assign data_out = mem[addr];. Use $monitor to print the stored data.