用 verilog 写一个 FT601Q 驱动

FT601Q 是一款高速 USB3.0 至 FIFO 桥接器，其驱动需要跟 USB 主机进行通信并控制 FIFO 的读写。以下是一个简单的 FT601Q 驱动的 Verilog 示例代码：

module FT601Q(
    input clk,
    input rst_n,
    input usb_clk,
    input usb_rst_n,
    input [1:0] usb_ep,
    input [15:0] fifo_data_in,
    output [15:0] fifo_data_out,
    output fifo_rd_n,
    output fifo_wr_n,
    output [1:0] fifo_sel
);

reg [7:0] usb_addr;
reg [15:0] usb_data_in, usb_data_out;
reg usb_rd_n, usb_wr_n;

// USB3.0 控制逻辑
always @(posedge usb_clk or negedge usb_rst_n) begin
    if (~usb_rst_n) begin
        usb_addr <= 0;
        usb_data_in <= 0;
        usb_rd_n <= 1;
        usb_wr_n <= 1;
    end else begin
        case (usb_addr)
            8'h00:
                usb_data_out <= 16'h0000; // Device ID
            8'h01:
                usb_data_out <= 16'h0100; // Vendor ID
            8'h02:
                usb_data_out <= 16'h0001; // Product ID
            8'h03:
                usb_data_out <= 16'h0100; // Device release number
            8'h04:
                usb_data_out <= 16'h0040; // Maximum packet size
            8'h05:
                usb_data_out <= 16'h0001; // FIFO interface number
            8'h06:
                usb_data_out <= 16'h0200; // Device release number
            8'h07:
                usb_data_out <= 16'h0001; // Number of configurations
            8'h80:
                usb_data_out <= {2'b00, 1'b0, fifo_sel}; // FIFO control register
            8'h81:
                usb_data_out <= fifo_data_out; // FIFO data register
            default:
                usb_data_out <= 16'h0000; // Default value
        endcase

        if (~usb_rd_n) begin
            case (usb_addr)
                8'h80:
                    fifo_rd_n <= 0;
                8'h81:
                    fifo_data_out <= 16'h0000;
                default:
                    fifo_rd_n <= 1;
            endcase
        end else begin
            fifo_rd_n <= 1;
        end

        if (~usb_wr_n) begin
            case (usb_addr)
                8'h80:
                    fifo_wr_n <= 0;
                    fifo_sel <= usb_data_in[1:0];
                8'h81:
                    fifo_wr_n <= 0;
                    fifo_data_in <= usb_data_in;
                default:
                    fifo_wr_n <= 1;
            endcase
        end else begin
            fifo_wr_n <= 1;
        end

        if (usb_ep == 2'b01) begin
            usb_data_in <= 16'h0000; // Acknowledge read
            usb_rd_n <= 1;
        end else if (usb_ep == 2'b10) begin
            usb_rd_n <= 0;
        end else if (usb_ep == 2'b11) begin
            usb_wr_n <= 0;
        end else begin
            usb_rd_n <= 1;
            usb_wr_n <= 1;
        end

        if (usb_ep == 2'b01 || usb_ep == 2'b10 || usb_ep == 2'b11) begin
            usb_addr <= usb_data_in[7:0];
        end
    end
end

// FIFO 控制逻辑
always @(posedge clk or negedge rst_n) begin
    if (~rst_n) begin
        fifo_sel <= 2'b00;
        fifo_rd_n <= 1;
        fifo_wr_n <= 1;
    end else begin
        fifo_sel <= 2'b00;
        fifo_rd_n <= 1;
        fifo_wr_n <= 1;

        if (~fifo_rd_n) begin
            fifo_data_out <= fifo_data_in;
        end
    end
end

endmodule

需要注意的是，这只是一个简单的示例代码，并不完整。在实际应用中，需要根据具体的设备和应用场景进行修改和完善。