串行乘法器

module ade(
clk,x,y,q
    );
 input clk;
 input [7:0]x,y;
 output [15:0]q;
 reg [15:0]q;
 parameter s0=0,s1=1,s2=2;
 reg [2:0]count=0;
 reg [1:0]state=0;
 reg [15:0]p1,t;
 reg [7:0]y_reg;
 always @ (posedge clk)
 begin
case(state)
s0:
begin
y_reg<=y;
state<=s1;
count<=0;
p1<=0;
t<={{8{x[7]}},x};
end
s1:
begin
if(count==7)
begin
state<=s2;
end
else
begin
if(y_reg[0]==1)
begin
p1<=p1+t;
y_reg<=y_reg>>1;
t<=t<<1;
count<=count+1;
state<=s1;
end
else
begin
p1<=p1;
y_reg<=y_reg>>1;
t<=t<<1;
count<=count+1;
state<=s1;
end
end
end
s2:
begin
q<=p1;
state<=s0;
end
endcase
 end
Endmodule