用systemverilog写个mdio接口转apb接口代码

以下是一个简单的SystemVerilog代码示例，用于将MDIO接口转换为APB接口：

module mdio_to_apb (
    input        logic                 clk,
    input        logic                 resetn,
    input  [4:0] logic                 mdio_addr,
    input  [4:0] logic                 mdio_reg,
    input        logic                 mdio_rd,
    input  [15:0] logic                 mdio_data_in,
    output [31:0] logic                 apb_addr,
    output [31:0] logic                 apb_data_out,
    output        logic                 apb_rd_en,
    output        logic                 apb_wr_en,
    output        logic                 apb_cs_n,
    output        logic                 apb_resetn
);

// Define APB register mapping
localparam APB_ADDR_OFFSET = 32'h10000000;
localparam APB_CTRL_REG = 0;
localparam APB_DATA_REG = 4;

// Define MDIO register mapping
localparam MDIO_CTRL_REG = 0;
localparam MDIO_STATUS_REG = 1;
localparam MDIO_PHYID_REG = 2;
localparam MDIO_PHYID2_REG = 3;
localparam MDIO_ANAD_REG = 4;
localparam MDIO_ANLPAD_REG = 5;

// Define internal registers
logic [15:0] mdio_data_out;
logic [31:0] apb_addr_reg;
logic        apb_rd_en_reg;
logic        apb_wr_en_reg;

// Control register
logic [31:0] ctrl_reg;
assign apb_addr = apb_addr_reg;
assign apb_data_out = ctrl_reg[31:0];
assign apb_rd_en = apb_rd_en_reg;
assign apb_wr_en = apb_wr_en_reg;
assign apb_cs_n = 1'b0;
assign apb_resetn = resetn;

always_ff @(posedge clk) begin
    // Read from MDIO
    if (mdio_rd) begin
        case (mdio_addr)
            MDIO_CTRL_REG: begin
                mdio_data_out = {mdio_data_in[0], ctrl_reg[31:1]};
            end
            MDIO_PHYID_REG: begin
                mdio_data_out = 16'h1234;
            end
            // Add additional cases for other MDIO registers here
        endcase
    end
    // Write to MDIO
    else if (!mdio_rd) begin
        case (mdio_addr)
            MDIO_CTRL_REG: begin
                mdio_data_out = mdio_data_in[15:1];
                ctrl_reg[31:1] = mdio_data_in[15:1];
            end
            // Add additional cases for other MDIO registers here
        endcase
    end

    // Generate APB address
    apb_addr_reg = APB_ADDR_OFFSET + (mdio_reg << 2);

    // Generate APB control signals
    if (mdio_rd) begin
        apb_rd_en_reg = 1'b1;
        apb_wr_en_reg = 1'b0;
    end
    else if (!mdio_rd) begin
        apb_rd_en_reg = 1'b0;
        apb_wr_en_reg = 1'b1;
    end

end

endmodule

该代码模块包括一个名为`mdio_to_apb`的模块，该模块将MDIO接口转换为APB接口。该模块包括一个时钟信号（`clk`）和复位信号（`resetn`），以及输入MDIO信号和输出APB信号。该模块还定义了一些内部寄存器和常数，用于将MDIO寄存器映射到APB寄存器。在时钟上升沿时，该模块读取MDIO接口并将数据写入APB接口，或者从APB接口读取数据并将其写入MDIO接口中。