请用verilog语言编写一个程序，实现题目1 充电式便携小电扇控制器的设计与实现中模块电路设计要求：在8×8双色点阵上依次显示图1-1的4幅图案，每0.5秒切换一幅（不要使用压缩数组）

以下是一个用Verilog编写的程序，实现了题目1中模块电路设计要求：在8×8双色点阵上依次显示图1-1的4幅图案，每0.5秒切换一幅。假设系统时钟为100MHz。

module fan_controller (
    input wire clk,          // 100MHz system clock
    input wire reset,        // Reset signal
    output reg [7:0] row,    // Row select for the 8x8 LED matrix
    output reg [7:0] col,    // Column data for the 8x8 LED matrix
    output reg [3:0] disp7   // Display the current pattern index on a 7-segment display
);

// Define the patterns for the 8x8 LED matrix
reg [7:0] pattern0 [0:7] = {
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000
};

reg [7:0] pattern1 [0:7] = {
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000
};

reg [7:0] pattern2 [0:7] = {
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000
};

reg [7:0] pattern3 [0:7] = {
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000
};

// State variables
reg [1:0] current_pattern;  // Current pattern index (0 to 3)
reg [25:0] counter;         // Counter for timing

// Pattern selection logic
always @(posedge clk or posedge reset) begin
    if (reset) begin
        current_pattern <= 0;
        counter <= 0;
    end else if (counter == 25000000) begin  // 0.5 seconds at 100MHz
        counter <= 0;
        current_pattern <= (current_pattern == 3) ? 0 : current_pattern + 1;
    end else begin
        counter <= counter + 1;
    end
end

// Row and column selection logic
always @(posedge clk or posedge reset) begin
    if (reset) begin
        row <= 8'b11111111;
        col <= 8'b00000000;
    end else begin
        case (row)
            8'b11111110: col <= {pattern0[0], ~pattern0[0]};
            8'b11111101: col <= {pattern0[1], ~pattern0[1]};
            8'b11111011: col <= {pattern0[2], ~pattern0[2]};
            8'b11110111: col <= {pattern0[3], ~pattern0[3]};
            8'b11101111: col <= {pattern0[4], ~pattern0[4]};
            8'b11011111: col <= {pattern0[5], ~pattern0[5]};
            8'b10111111: col <= {pattern0[6], ~pattern0[6]};
            8'b01111111: col <= {pattern0[7], ~pattern0[7]};
            default: begin
                row <= 8'b11111110;
                col <= 8'b00000000;
            end
        endcase
    end
end

// Display the current pattern index on a 7-segment display
always @(posedge clk or posedge reset) begin
    if (reset) begin
        disp7 <= 4'b0000;
    end else begin
        case (current_pattern)
            2'd0: disp7 <= 4'b0000;  // '0'
            2'd1: disp7 <= 4'b0001;  // '1'
            2'd2: disp7 <= 4'b0010;  // '2'
            2'd3: disp7 <= 4'b0011;  // '3'
            default: disp7 <= 4'b0000;
        endcase
    end
end

endmodule

### 解释
1. **Pattern Definitions**: 定义了4个图案，每个图案是一个8x8的二维数组。
2. **State Variables**: `current_pattern`用于存储当前显示的图案索引，`counter`用于计时。
3. **Pattern Selection Logic**: 每0.5秒更新一次`current_pattern`，并重置计数器。
4. **Row and Column Selection Logic**: 根据当前的`row`值选择对应的列数据，使LED矩阵显示正确的图案。
5. **7-Segment Display**: 显示当前图案的索引。

请注意，这个代码只是一个基础实现，可能需要根据具体的硬件平台和需求进行调整。