Parameters choose logic functionality

‘define ADD 0

‘define SUB 1

module addsub (a, b, c);

parameter width = 8;

parameter op = `ADD;

input [width-1:0] a, b;

output [width-1:0] c;

assign c = (op == `ADD) ? (a + b) : (a - b);

endmodule

...

addsub #(32,`SUB) c32(x, y, z);

...

Example: Choose adder or subtractor