写一个复杂得可综合得小型设计，我需要测试verilog，system verilog复杂得语法

以下是一个简单的Verilog模块，用于实现一个简单的带有流水线的CPU。该CPU包括一个指令存储器（IM），一个数据存储器（DM），一个指令译码器（ID），一个算术逻辑单元（ALU），一个寄存器堆（REG），以及多个流水线寄存器（IF/ID，ID/EX，EX/MEM，MEM/WB），以实现指令的流水线执行。

module cpu (
    input clk,
    input [31:0] reset,
    input [31:0] im_rd_addr,
    input [31:0] dm_rd_addr,
    input [31:0] dm_wr_addr,
    input [31:0] dm_wr_data,
    output reg [31:0] dm_rd_data,
    output reg [31:0] pc_out,
    output reg [31:0] ir_out,
    output reg [31:0] a_out,
    output reg [31:0] b_out,
    output reg [31:0] alu_out,
    output reg [31:0] reg_wr_addr,
    output reg [31:0] reg_wr_data
);

// Instruction memory
reg [31:0] im [0:1023];
always @(posedge clk) pc_out <= pc_out + 4;
assign ir_out = im[pc_out >> 2];
assign a_out = regfile[ir_out[25:21]];
assign b_out = regfile[ir_out[20:16]];

// Data memory
reg [31:0] dm [0:1023];
always @(posedge clk) dm_rd_data <= dm[dm_rd_addr >> 2];
always @(posedge clk) dm[dm_wr_addr >> 2] <= dm_wr_data;

// Instruction decoding
reg [4:0] opcode;
reg [1:0] aluop;
always @(posedge clk) begin
    opcode <= ir_out[31:27];
    aluop <= ir_out[5:4];
end

// Arithmetic logic unit
reg [31:0] alu_a;
reg [31:0] alu_b;
always @(posedge clk) begin
    alu_a <= a_out;
    alu_b <= b_out;
end
reg [31:0] alu_out;
always @(posedge clk) begin
    case (aluop)
        2'b00: alu_out <= alu_a + alu_b;
        2'b01: alu_out <= alu_a - alu_b;
        2'b10: alu_out <= alu_a & alu_b;
        2'b11: alu_out <= alu_a | alu_b;
    endcase
end

// Register file
reg [31:0] regfile [0:31];
reg [4:0] reg_wr_addr;
reg [31:0] reg_wr_data;
always @(posedge clk) begin
    reg_wr_addr <= ir_out[20:16];
    reg_wr_data <= alu_out;
end
always @(posedge clk) regfile[0] <= 0;
always @(posedge clk) begin
    if (reg_wr_addr != 0)
        regfile[reg_wr_addr] <= reg_wr_data;
end

// Pipeline registers
reg [31:0] if_id_reg;
reg [31:0] id_ex_reg;
reg [31:0] ex_mem_reg;
reg [31:0] mem_wb_reg;
always @(posedge clk) begin
    if_id_reg <= ir_out;
    id_ex_reg <= {alu_a, alu_b, alu_out, reg_wr_addr, reg_wr_data};
    ex_mem_reg <= {alu_out, reg_wr_addr, reg_wr_data};
    mem_wb_reg <= {alu_out, reg_wr_addr, reg_wr_data};
end

// Pipeline stages
always @(posedge clk) begin
    pc_out <= pc_out + 4;
    ir_out <= im[pc_out >> 2];
    a_out <= regfile[ir_out[25:21]];
    b_out <= regfile[ir_out[20:16]];
end
always @(posedge clk) begin
    case (opcode)
        5'd0: aluop <= 2'b00; // ADD
        5'd1: aluop <= 2'b01; // SUB
        5'd2: aluop <= 2'b10; // AND
        5'd3: aluop <= 2'b11; // OR
        default: aluop <= 2'b00; // Default for invalid opcodes
    endcase
end
always @(posedge clk) begin
    case (aluop)
        2'b00: alu_out <= alu_a + alu_b;
        2'b01: alu_out <= alu_a - alu_b;
        2'b10: alu_out <= alu_a & alu_b;
        2'b11: alu_out <= alu_a | alu_b;
    endcase
end
always @(posedge clk) begin
    reg_wr_addr <= ir_out[20:16];
    reg_wr_data <= alu_out;
end
always @(posedge clk) begin
    if (reg_wr_addr != 0)
        regfile[reg_wr_addr] <= reg_wr_data;
end
always @(posedge clk) begin
    if_id_reg <= ir_out;
    id_ex_reg <= {alu_a, alu_b, alu_out, reg_wr_addr, reg_wr_data};
    ex_mem_reg <= {alu_out, reg_wr_addr, reg_wr_data};
    mem_wb_reg <= {alu_out, reg_wr_addr, reg_wr_data};
end

endmodule

该模块包括一个时钟输入、一个复位输入、多个存储器读写地址和数据输入、多个输出端口以及多个模块内部信号。它实现了一个简单的带有流水线的CPU，包括指令存储器、数据存储器、指令译码器、算术逻辑单元、寄存器堆以及多个流水线寄存器。每个流水线寄存器都实现了一个简单的时序逻辑，将前一级的结果暂存，并在适当的时候传递给下一级。指令的流水线执行通过一系列的时序逻辑实现，包括指令译码、算术逻辑运算、寄存器读写等操作。