verilog localparam
时间: 2023-10-15 16:08:27 浏览: 33
In Verilog, localparam is a keyword used to define a parameter that is local to a module or block. It is similar to a parameter, but its scope is limited to the module or block where it is defined.
Localparam can be used to define constants, values, or other parameters that are used within a module or block. They are typically used to simplify the code and make it more readable by giving meaningful names to values or constants.
Localparam can be assigned a value during declaration, or it can be assigned a value using an initial block. Localparam values cannot be changed during simulation and are therefore constant.
Here is an example of how localparam can be used:
```
module my_module(
input [7:0] data_in,
output [7:0] data_out
);
localparam ADDER_WIDTH = 8;
localparam MULTIPLIER_WIDTH = 16;
wire [ADDER_WIDTH-1:0] add_result;
wire [MULTIPLIER_WIDTH-1:0] mul_result;
assign add_result = data_in + 8'hFF;
assign mul_result = data_in * 16'hFFFF;
assign data_out = add_result[7:0] + mul_result[15:8];
endmodule
```
In this example, localparam is used to define the width of the adder and multiplier operations. These values are used to define the size of the wires used to store the results of the operations, making the code more readable and easier to understand.