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发表于 2011-6-10 11:33:41
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例2-26 用Verilog HDL实现一个4位的流水线乘法器
module mul_addtree(mul_a, mul_b, mul_out, clk, rst_n);
parameter MUL_WIDTH = 4;
parameter MUL_RESULT = 8;
input [MUL_WIDTH-1 : 0] mul_a;
input [MUL_WIDTH-1 : 0] mul_b;
input clk;
input rst_n;
output [MUL_RESULT-1 : 0] mul_out;
reg [MUL_RESULT-1 : 0] mul_out;
reg [MUL_RESULT-1 : 0] stored0;
reg [MUL_RESULT-1 : 0] stored1;
reg [MUL_RESULT-1 : 0] stored2;
reg [MUL_RESULT-1 : 0] stored3;
reg [MUL_RESULT-1 : 0] add01;
reg [MUL_RESULT-1 : 0] add23;
always @ (posedge clk or negedge rst_n)
begin
if(!rst_n)
begin //初始化寄存器变量
mul_out <= 8'b0000_0000;
stored0 <= 8'b0000_0000;
stored1 <= 8'b0000_0000;
stored2 <= 8'b0000_0000;
stored3 <= 8'b0000_0000;
add01 <= 8'b0000_0000;
add23 <= 8'b0000_0000;
end
else
begin //实现移位相加
stored3 <= mul_b[3]?{1'b0,mul_a,3'b0}: 8'b0;
stored2 <= mul_b[2]?{2'b0,mul_a,2'b0}: 8'b0;
stored1 <= mul_b[1]?{3'b0,mul_a,1'b0}: 8'b0;
stored0 <= mul_b[0]?{4'b0,mul_a}: 8'b0;
add01 <= stored1 + stored0;
add23 <= stored3 + stored2;
mul_out <= add01 + add23;
end
end
endmodule |
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