用verilog实现LBIST，要求：包含8位LFSR，MCU可以发送自定义LFSR的seed或使用默认的LFSR值（0xB2），执行预定义的计算，并进行验证。验证正确，会产生新的伪随机数；验证错误，输出错误信号。

以下是实现LBIST的Verilog代码，包括8位LFSR和验证模块。MCU可以通过“lfsr_seed”输入端口发送自定义种子值，或者使用默认值0xB2。验证正确时，“pass”输出端口将产生高电平信号，否则，“fail”输出端口将产生高电平信号。

module LBIST(
    input clk,
    input reset,
    input [7:0] lfsr_seed,
    output reg pass,
    output reg fail
);

reg [7:0] lfsr;
reg [7:0] lfsr_out;
wire lfsr_tap = lfsr[5] ^ lfsr[3];

// LFSR
always @(posedge clk) begin
    if (reset) begin
        lfsr <= 0;
    end else begin
        lfsr <= {lfsr[6:0], lfsr_tap};
    end
end

// Validation
always @(posedge clk) begin
    if (reset) begin
        pass <= 0;
        fail <= 0;
        lfsr_out <= 0;
    end else begin
        if (lfsr == 8'hB2) begin
            // Default seed value
            lfsr_out <= lfsr;
            pass <= 1;
            fail <= 0;
        end else if (lfsr == lfsr_seed) begin
            // Custom seed value
            lfsr_out <= lfsr;
            pass <= 1;
            fail <= 0;
        end else begin
            // Incorrect LFSR output
            lfsr_out <= lfsr;
            pass <= 0;
            fail <= 1;
        end
    end
end

endmodule