Microsoft Word - Digital Logic Design v_4_6a

7.9. Code Modularization

As the code gets more complex and size increases, it is important to modularize the code by developing
the code as multiple modules. This approach improves code reusability, improved debugging/reliability
and simpler design.

Here is example of how multiple modules are used:

// Modularized code

// First write the module you plan to use latter

module mod_base(inA,inB,outA);

input inA,inB;

wire inA, inB

output outA;

reg outA;

assign outA=(inA)?inB:1’b0;

endmodule

// now write the main circuit that uses our selector

module main(a,b);

input a,;

wire a;

output b;

reg b;

// now used mod_base

mod_base U1(1’b0,1’b1, temp); // this is where the mod-base is instantiated and used.

endmodule