用verilog写一个AXI4的Master接口

好的，以下是一个简单的 AXI4 Master 接口的 Verilog 代码实现：

module axi_master (
    input  clk,        // 时钟信号
    input  reset,      // 复位信号
    output [31:0] addr,// 地址信号
    output [31:0] wdata,// 写数据信号
    output        wvalid,// 写有效信号
    input         wready,// 写就绪信号
    input         bvalid,// 写响应有效信号
    output        bready,// 写响应就绪信号
    output [31:0] rdata,// 读数据信号
    output        rvalid,// 读有效信号
    input         rready // 读就绪信号
);

    // 内部寄存器
    reg [31:0] addr_reg;
    reg [31:0] wdata_reg;
    reg        wvalid_reg;
    reg        bready_reg;
    reg [31:0] rdata_reg;
    reg        rvalid_reg;

    // 写数据状态机
    localparam IDLE = 2'b00;
    localparam ADDR = 2'b01;
    localparam DATA = 2'b10;
    localparam RESP = 2'b11;
    reg [1:0] wstate;
    
    always @(posedge clk) begin
        if (reset) begin
            wstate <= IDLE;
            addr_reg <= 0;
            wdata_reg <= 0;
            wvalid_reg <= 0;
            bready_reg <= 0;
        end else begin
            case (wstate)
                IDLE: begin
                    if (wvalid && wready) begin
                        addr_reg <= addr;
                        wdata_reg <= wdata;
                        wvalid_reg <= 1;
                        bready_reg <= 1;
                        wstate <= ADDR;
                    end
                end
                ADDR: begin
                    if (bvalid && bready) begin
                        wvalid_reg <= 0;
                        bready_reg <= 0;
                        wstate <= DATA;
                    end
                end
                DATA: begin
                    if (wvalid && wready) begin
                        wdata_reg <= wdata;
                    end
                    if (bvalid && bready) begin
                        wvalid_reg <= 0;
                        bready_reg <= 0;
                        wstate <= RESP;
                    end
                end
                RESP: begin
                    if (rready && rvalid) begin
                        rdata_reg <= rdata;
                        rvalid_reg <= 0;
                        wstate <= IDLE;
                    end
                end
            endcase
        end
    end
    
    // 读数据状态机
    localparam READ_IDLE = 2'b00;
    localparam READ_ADDR = 2'b01;
    localparam READ_RESP = 2'b10;
    reg [1:0] rstate;
    
    always @(posedge clk) begin
        if (reset) begin
            rstate <= READ_IDLE;
            addr_reg <= 0;
            rvalid_reg <= 0;
        end else begin
            case (rstate)
                READ_IDLE: begin
                    if (rvalid && rready) begin
                        addr_reg <= addr;
                        rvalid_reg <= 1;
                        rstate <= READ_ADDR;
                    end
                end
                READ_ADDR: begin
                    if (rvalid && rready) begin
                        rvalid_reg <= 0;
                        rstate <= READ_RESP;
                    end
                end
                READ_RESP: begin
                    if (rready && rvalid) begin
                        rdata_reg <= rdata;
                        rvalid_reg <= 0;
                        rstate <= READ_IDLE;
                    end
                end
            endcase
        end
    end
    
    // 输出信号
    assign addr = addr_reg;
    assign wdata = wdata_reg;
    assign wvalid = wvalid_reg;
    assign bready = bready_reg;
    assign rdata = rdata_reg;
    assign rvalid = rvalid_reg;

endmodule

该代码实现了 AXI4 Master 接口的写和读功能，通过状态机控制发送和接收数据的过程，并且处理了写和读的响应信号。当写请求被发送时，会等待写响应信号的到来，然后发送数据；当读请求被发送时，会等待读响应信号的到来，然后接收数据。请注意，此代码实现仅用于示例目的。实际使用中，需要对其进行适当的修改和调整以满足具体的需求。