Half Subtractor (Dataflow Modeling)

Half Subtractor (Dataflow Modeling):

module half_sub(

    input a,

    input b,

    output diff,

    output borrow

    );

assign diff=a^b;

assign borrow=(~a)&b;

endmodule

 

Full Subtractor (Dataflow Modeling):

 

module full_sub(

    input a,

    input b,

    input c,

    output diff,

    output borrow

    );

assign x= b^c;

assign diff = a ^ x;

assign n1=~c;

assign y=b & n1;

assign n2=~x;

assign z=a & n2;

assign borrow = y | z;

endmodule