I want to take in a parameter and assign a number of zeroes equal to the paramter to a constant, and use this constant for comparison. how do I do it ?
For example, say parameter is 3, I want to create a constant
n=3'b000;
and use this n in another statement. Only thing is, I don't know n. How do i initialize 'n' zeroes and to what verilog data type do I assign it to ?
Your looking for the replication operator. The syntax is {replication_constant{value}}.
An example of creating a bus of size WIDTH to all zeros.
parameter WIDTH = 3;
wire [WIDTH-1:0] n = {WIDTH{1'b0}};
For full description of the replication operator, see IEEE std 1800-2012 § 11.4.12.1 "Replication operator"
'0) is for SystemVerilog, the SO's question is for Verilog.
1'b0 with whatever value you want, such as 1'b1 for all 1s. SV has fill values '0,'1,'x,'z (case insensitive).To expand Gregs answer and answer what if you wanted 1 then all 0's.
Use a mixture of concatenation {a,b} and replication {width{c}}:
wire [WIDTH-1:0] n = { 1'b1, {WIDTH-1{1'b0}} } ;
While the '0 or '1 syntax is in use in SystemVerilog 'b0 for width matching is valid in older Verilog. In verilog-95 it would only width match upto 32 bits but that has since been rectified.
Example defining the reset values on flip-flops :
reg [7:0] a;
always @(posedge clk or negedge rst_n) begin
if(~rst_n) begin
a <= 'b0 ;
...
