基于fpga的m序列发生器代码
时间: 2023-08-07 13:07:30 浏览: 33
以下是基于 FPGA 的 M 序列发生器的代码示例:
```verilog
module m_sequence_generator(
input clk,
input rst,
input [4:0] polynomial,
input [3:0] seed,
output reg m_seq_out
);
reg [3:0] state;
reg feedback;
reg [4:0] poly_taps [15:0];
// Generate polynomial taps
always @* begin
case(polynomial)
5'b00001: poly_taps = {1,0,0,0,1};
5'b00011: poly_taps = {1,0,0,1,1};
5'b00101: poly_taps = {1,0,1,0,1};
5'b01001: poly_taps = {1,0,0,0,1};
5'b10001: poly_taps = {1,0,0,0,1};
default: poly_taps = {1,0,0,0,1};
endcase
end
// Generate feedback
always @(posedge clk, posedge rst) begin
if(rst) begin
state <= seed;
feedback <= 1;
end else begin
feedback <= state[0] ^ state[poly_taps[0]] ^ state[poly_taps[1]] ^ state[poly_taps[2]] ^ state[poly_taps[3]] ^ state[poly_taps[4]];
state <= {feedback, state[0:3]};
end
end
// Output M sequence
always @(posedge clk) begin
m_seq_out <= state[3];
end
endmodule
```
该模块使用一个 5 位的多项式来生成序列。多项式的选择可以根据需要进行更改。在每个时钟周期中,该模块将更新状态寄存器并输出 M 序列的下一个值。