Verilog实现串/并行加法器

实现两个N位二进制数dataa、datab的乘积,用简单的方法计算就是利用移位操作来实现。dataa进行位扩展左移累加的操作，datab不便右移的操作。

module Multiply(
clk,rst,
dataa,datab,
dout
);
input clk; 
input rst;
input [7:0] dataa;
input [7:0] datab;
output reg[15:0] dout; 
parameter s1 = 0,s2=1,s3=2;
 
//reg [7:0]dataareg;
reg [7:0]databreg;
reg [1:0]state;
 
reg [15:0]tmp;
reg [15:0]dreg;
reg [2:0]count;
always@(posedge clk or negedge rst)
if(!rst)
begin
tmp<=16'b0;
databreg<=8'd0;
state<=0;
//state<=s1;
end
else
case(state)
s1:begin
//tmp<={{8{dataareg[7]}},dataareg};
dreg<=16'd0;
count<=3'd0;
tmp<={{8{dataa[7]}},dataa};
//$dispaly("number %d",tmp);
state<=s2;
databreg<=datab;
end
s2:begin
if(count==7)
state<=s3;
else begin
if(databreg[0]==1)
dreg<=tmp+dreg;
//else
databreg<=databreg>>1;
tmp <= tmp<<1;
//$
//$dispaly("number %d",tmp);
count =count+1;
 
state<=s2;
end
end
s3:begin
dout<=dreg;
state<=s1;
end
endcase 
endmodule
 

选择器件是cycloneII系列

环境是：quartusII11.0