FPGA应用74HC595根据上位机输入控制LED亮灭代码示例

以下是一个FPGA应用74HC595实现根据上位机输入控制LED亮灭的Verilog代码示例：

module led_controller(
    input clk,
    input rst,
    input [7:0] data_in,
    output reg [7:0] shift_out
);

reg [7:0] data_reg;

reg [2:0] state;
parameter IDLE = 3'b000, START = 3'b001, SHIFT = 3'b010, LATCH = 3'b011;

assign shift_out[0] = data_reg[7];
assign shift_out[1] = data_reg[6];
assign shift_out[2] = data_reg[5];
assign shift_out[3] = data_reg[4];
assign shift_out[4] = data_reg[3];
assign shift_out[5] = data_reg[2];
assign shift_out[6] = data_reg[1];
assign shift_out[7] = data_reg[0];

always @(posedge clk, posedge rst) begin
    if(rst) begin
        state <= IDLE;
        data_reg <= 8'b0;
    end else begin
        case(state)
            IDLE: begin
                if(data_in != 8'b0) begin
                    state <= START;
                    data_reg <= data_in;
                end
            end
            START: begin
                state <= SHIFT;
            end
            SHIFT: begin
                data_reg <= {data_reg[6:0], data_reg[7]};
                if(state == LATCH) begin
                    state <= IDLE;
                end else begin
                    state <= SHIFT;
                end
            end
            LATCH: begin
                state <= IDLE;
            end
        endcase
    end
end

always @(posedge clk) begin
    if(state == START) begin
        shift_out <= 8'b11111111;
    end else if(state == SHIFT) begin
        shift_out <= {1'b0, shift_out[7:1]};
    end else if(state == LATCH) begin
        shift_out <= 8'b00000000;
    end else begin
        shift_out <= shift_out;
    end
end

endmodule

这个代码实现了一个简单的LED控制器，可以接收8位数据作为LED的状态控制信号。数据通过74HC595进行移位寄存器控制，并输出到LED。

需要注意的是，这里只是一个简单的示例代码，具体实现方式和代码细节可能会因不同的硬件平台和通信协议而有所不同。因此，建议您参考相关的硬件和软件文档，并根据实际情况进行调试和优化。