用verilog编写axi stream接口的图像缩放算法

以下是一个基于AXI Stream接口的图像缩放算法的Verilog实现，其中采用了双线性插值法来实现图像缩放：

module image_scaler (
  input aclk, // Clock
  input aresetn, // Asynchronous reset
  input s_axi_aclk, // AXI Stream clock
  input s_axi_aresetn, // AXI Stream reset
  input [31:0] s_axi_awaddr, // Write address
  input [7:0] s_axi_awlen, // Write burst length
  input [2:0] s_axi_awsize, // Write burst size
  input [1:0] s_axi_awburst, // Write burst type
  input [1:0] s_axi_awcache, // Write cache type
  input [3:0] s_axi_awprot, // Write protection type
  input s_axi_wready, // Write ready
  input [31:0] s_axi_wdata, // Write data
  input [3:0] s_axi_wstrb, // Write strobe
  input s_axi_bready, // Write response ready
  output [1:0] s_axi_bresp, // Write response
  input [31:0] s_axi_araddr, // Read address
  input [7:0] s_axi_arlen, // Read burst length
  input [2:0] s_axi_arsize, // Read burst size
  input [1:0] s_axi_arburst, // Read burst type
  input [1:0] s_axi_arcache, // Read cache type
  input [3:0] s_axi_arprot, // Read protection type
  input s_axi_rready, // Read response ready
  output [31:0] s_axi_rdata, // Read data
  output s_axi_rvalid, // Read response valid
  output [1:0] s_axi_rresp, // Read response
  input s_axi_rlast, // Read last
  input [7:0] input_width, // Input image width
  input [7:0] input_height, // Input image height
  input [31:0] input_start_addr, // Input image start address
  input [7:0] output_width, // Output image width
  input [7:0] output_height, // Output image height
  input [31:0] output_start_addr // Output image start address
);

parameter DATA_WIDTH = 32;

// Calculate scale factors
localparam SCALE_FACTOR_X = input_width / output_width;
localparam SCALE_FACTOR_Y = input_height / output_height;

reg [DATA_WIDTH-1:0] pixel_buffer [0:SCALE_FACTOR_X-1][0:SCALE_FACTOR_Y-1];
// Buffer to hold pixels for interpolation

reg [31:0] input_address = input_start_addr;
reg [31:0] output_address = output_start_addr;
reg [7:0] input_x = 0;
reg [7:0] input_y = 0;
reg [7:0] output_x = 0;
reg [7:0] output_y = 0;
reg [1:0] rresp = 0;

integer i, j;
reg [DATA_WIDTH-1:0] p00, p01, p10, p11;
reg [DATA_WIDTH-1:0] p0x, p1x, px0, px1, pxy;

always @(posedge aclk or negedge aresetn) begin
  if (~aresetn) begin
    input_address <= input_start_addr;
    output_address <= output_start_addr;
    input_x <= 0;
    input_y <= 0;
    output_x <= 0;
    output_y <= 0;
    rresp <= 0;
  end else begin
    // Write data to buffer
    if (s_axi_wready && (s_axi_awburst == 1'b1)) begin
      pixel_buffer[s_axi_awaddr[2:0]][s_axi_awaddr[6:3]] <= s_axi_wdata;
      s_axi_bresp <= 0;
    end else if (!s_axi_wready && (s_axi_awburst == 1'b1)) begin
      s_axi_bresp <= 2'b10; // Slave not ready
    end else if (s_axi_wready && (s_axi_awburst == 1'b0)) begin
      pixel_buffer[s_axi_awaddr[2:0]][s_axi_awaddr[6:3]] <= s_axi_wdata;
      s_axi_awaddr <= s_axi_awaddr + 4;
      s_axi_awlen <= s_axi_awlen - 1;
      if (s_axi_awlen == 0) begin
        s_axi_bresp <= 0;
      end
    }

    // Read data from buffer
    if (s_axi_rready) begin
      s_axi_rdata <= pixel_buffer[output_x % SCALE_FACTOR_X][output_y % SCALE_FACTOR_Y];
      s_axi_rvalid <= 1;
      s_axi_rlast <= (output_x == output_width-1) && (output_y == output_height-1);
      s_axi_rresp <= rresp;
      if (s_axi_rlast) begin
        output_x <= 0;
        output_y <= 0;
        output_address <= output_address + 4;
      end else begin
        output_x <= output_x + 1;
        if (output_x == output_width-1) begin
          output_x <= 0;
          output_y <= output_y + 1;
        end
      end
    } else begin
      s_axi_rvalid <= 0;
      s_axi_rlast <= 0;
      s_axi_rresp <= 0;
    }

    // Interpolate pixels
    if ((input_x < input_width) && (input_y < input_height)) begin
      p00 = $readmemh({input_address, 2'h0})[31:0];
      p01 = $readmemh({input_address+4, 2'h0})[31:0];
      p10 = $readmemh({input_address+(input_width*4), 2'h0})[31:0];
      p11 = $readmemh({input_address+(input_width*4)+4, 2'h0})[31:0];

      p0x = (input_x+1)*p01 + (input_width-input_x-1)*p00;
      p1x = (input_x+1)*p11 + (input_width-input_x-1)*p10;
      px0 = (input_y+1)*p10 + (input_height-input_y-1)*p00;
      px1 = (input_y+1)*p11 + (input_height-input_y-1)*p01;

      pxy = (input_x+1)*(input_y+1)*p11 +
            (input_width-input_x-1)*(input_y+1)*p10 +
            (input_x+1)*(input_height-input_y-1)*p01 +
            (input_width-input_x-1)*(input_height-input_y-1)*p00;

      pixel_buffer[input_x % SCALE_FACTOR_X][input_y % SCALE_FACTOR_Y] <= pxy;
    end

    // Advance input address
    if ((input_x < input_width) && (input_y < input_height)) begin
      input_x <= input_x + SCALE_FACTOR_X;
      if (input_x >= input_width) begin
        input_x <= 0;
        input_y <= input_y + SCALE_FACTOR_Y;
        if (input_y >= input_height) begin
          input_y <= 0;
          input_address <= input_address + (input_width*4);
        end
      end
    }

    // Check for read response errors
    if (s_axi_rvalid && !s_axi_rready) begin
      rresp <= 2'b10; // Slave not ready
    end else if (!s_axi_rvalid && s_axi_rready) begin
      rresp <= 2'b11; // Data not available
    end else begin
      rresp <= 2'b00;
    end
  end
end

endmodule

上述代码包含了AXI Stream接口的所有信号，包括写地址、写数据、写响应、读地址、读数据、读响应等。在算法实现中，通过双线性插值法实现图像缩放，并使用一个缓冲区存储待插值的像素。该算法支持一次写入多个像素，可以通过一次写入多个像素来提高效率。