2路组相联cache设计代码

以下是一个简单的 2 路组相联 Cache 的 Verilog 代码示例：

module cache(
  input clk,
  input rst,
  input [31:0] addr,
  input [31:0] data_in,
  input we,
  output [31:0] data_out,
  output hit
);
  parameter TAG_WIDTH = 20;
  parameter INDEX_WIDTH = 6;
  parameter BLOCK_WIDTH = 4;
  parameter CACHE_SIZE = 64;

  reg [CACHE_SIZE-1:0] tag_mem_0;
  reg [CACHE_SIZE-1:0] tag_mem_1;
  reg [CACHE_SIZE-1:0] data_mem_0;
  reg [CACHE_SIZE-1:0] data_mem_1;
  reg [INDEX_WIDTH-1:0] index;
  reg [TAG_WIDTH-1:0] tag;
  reg [BLOCK_WIDTH-1:0] block;
  reg [31:0] data;

  wire [CACHE_SIZE-1:0] tag_0;
  wire [CACHE_SIZE-1:0] tag_1;
  wire [CACHE_SIZE-1:0] data_0;
  wire [CACHE_SIZE-1:0] data_1;
  wire hit_0;
  wire hit_1;

  // Calculate index, tag, and block from address
  assign index = addr[INDEX_WIDTH+BLOCK_WIDTH-1:BLOCK_WIDTH];
  assign tag = addr[TAG_WIDTH+INDEX_WIDTH+BLOCK_WIDTH-1:INDEX_WIDTH+BLOCK_WIDTH];
  assign block = addr[BLOCK_WIDTH-1:0];

  // Read from both ways
  assign tag_0 = tag_mem_0 & (index == {CACHE_SIZE/{(2**(INDEX_WIDTH)))}}'b1);
  assign tag_1 = tag_mem_1 & (index == {CACHE_SIZE/{(2**(INDEX_WIDTH)))}}'b1);
  assign data_0 = data_mem_0 & (index == {CACHE_SIZE/{(2**(INDEX_WIDTH)))}}'b1);
  assign data_1 = data_mem_1 & (index == {CACHE_SIZE/{(2**(INDEX_WIDTH)))}}'b1);
  assign hit_0 = (tag_0 == tag) ? 1'b1 : 1'b0;
  assign hit_1 = (tag_1 == tag) ? 1'b1 : 1'b0;

  // Write to both ways if there is a miss
  always @(posedge clk) begin
    if (rst) begin
      tag_mem_0 <= 'b0;
      tag_mem_1 <= 'b0;
      data_mem_0 <= 'b0;
      data_mem_1 <= 'b0;
    end else if (we && !hit_0 && !hit_1) begin
      tag_mem_0[index] <= tag;
      data_mem_0[index] <= data_in;
    end else if (we && hit_0 && !hit_1) begin
      data_mem_0[index] <= data_in;
    end else if (we && !hit_0 && hit_1) begin
      tag_mem_0[index] <= tag;
      data_mem_1[index] <= data_in;
    end else if (we && hit_0 && hit_1) begin
      data_mem_0[index] <= data_in;
    end
  end

  // Read from the way that has a hit
  always @(*) begin
    if (hit_0) begin
      data = data_0[index];
    end else if (hit_1) begin
      data = data_1[index];
    end
    data_out = data;
    hit = hit_0 | hit_1;
  end

endmodule

该代码使用了一些常量参数来定义 Cache 的大小和索引、标记、块的位宽。它还使用了两个标记和数据存储器来存储两个路的标记和数据。在每个时钟周期中，代码使用地址计算索引、标记和块，并从两个路中读取标记和数据。如果命中，则从相应的路中读取数据并设置 hit 信号为 1，否则写入数据并设置 hit 信号为 0。