Multiplication is the easy way of addition. For multiplication
multipliers are used. It is used in Multipliers and accumulators, Digital signal
processing such as convolution, windows techniques, etc. In further coming sessions
we are going to see the types of multipliers which are used.
First we are going to
see the Simple Multipliers and Array multipliers.
3.1 Simple multiplier:
module mul(a,b,s);
input [3:0]a;
input [3:0]b;
output [7:0]s;
assign s = a*b;
endcmodule
3.2 ARRAY
MULTIPLIER:
module mul (product,inp1,inp2);
output [7:0]product;
input [3:0]inp1;
input [3:0]inp2;
assign product[0]=(inp1[0]&inp2[0]);
wire
x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15,x16,x17;
HA
HA1(product[1],x1,(inp1[1]&inp2[0]),(inp1[0]&inp2[1]));
FA
FA1(x2,x3,inp1[1]&inp2[1],(inp1[0]&inp2[2]),x1);
FA
FA2(x4,x5,(inp1[1]&inp2[2]),(inp1[0]&inp2[3]),x3);
HA HA2(x6,x7,(inp1[1]&inp2[3]),x5);
HA
HA3(product[2],x15,x2,(inp1[2]&inp2[0]));
FA
FA5(x14,x16,x4,(inp1[2]&inp2[1]),x15);
FA FA4(x13,x17,x6,(inp1[2]&inp2[2]),x16);
FA
FA3(x9,x8,x7,(inp1[2]&inp2[3]),x17);
HA
HA4(product[3],x12,x14,(inp1[3]&inp2[0]));
FA
FA8(product[4],x11,x13,(inp1[3]&inp2[1]),x12);
FA
FA7(product[5],x10,x9,(inp1[3]&inp2[2]),x11);
FA
FA6(product[6],product[7],x8,(inp1[3]&inp2[3]),x10);
Endmodule
module HA(sout,cout,a,b);
output sout,cout;
input a,b;
assign sout=a^b;
assign cout=(a&b);
endmodule
module FA(sout,cout,a,b,cin);
output sout,cout;
input a,b,cin;
assign sout=(a^b^cin);
assign
cout=((a&b)|(a&cin)|(b&cin));
endmodule
