Verilog 程式錯誤除錯

分析Verilog代码

我正在阅读snakeGameV3 Verilog代码，查看输出和输入信号，识别寄存器和内存位置，以及各种计时器。这让我能够整体把握代码的功能和结构。

初始化和逻辑操作

我正在分析初始化块，包括seg_code和LED输出，设置使能和通信信号，确定七段显示逻辑和时钟生成逻辑，处理暂停和增加计数器，以及使能LED显示逻辑。

跟踪状态变化

观察LED颜色变化，更新移动方向和蛇身，刷新地图上的项目位置，解决Verilog数组索引问题。

奇怪组合使用

Verilog数组声明和索引结合使用时，出现了奇怪的组合，可能导致索引超出范围。需要检查非阻塞赋值符号的使用情况。

混合赋值符号的问题

混用阻塞和非阻塞赋值符号可能导致问题。在'system_clk'块中，game_clk和led_clk没有重置。初始块在某些FPGA上不可合成。

更新核对

检查item_x和item_y的位数问题，确保game_clk和其他操作正确。更新七段显示需要考虑digit和point的位数差异。

问题发现

发现point存储为二进制形式，更新显示需要转换为BCD。map数组未进行初始化，可能包含未定义的位。comm作为列计数器映射到item_x。

解决竞态条件
考虑将LedR的组合块更改为顺序块，以避免竞态条件。使用顺序块可以在赋值时保存之前的状态，防止数据丢失。

调试并修复

我正在调试程序，列出错误并提建议。关键错误包括使用阻塞赋值、组合赋值导致抖动、item_x和item_y的计算问题。

分析问题

点数以二进制形式存储，显示时需转换为BCD格式。地图数组未初始化，可能包含未定义位。竞态条件解决仍需深入研究。

思考 花的時間為 13 秒

Certainly! Let's go through your Verilog code for the snakeGameV3 module step by step to identify and debug potential issues. I'll highlight the problems and provide suggestions for corrections to ensure the program functions as intended.

1. Incorrect Use of Blocking (=) vs. Nonblocking (<=) Assignments

Issue:

In sequential always blocks (those triggered by clock edges), using blocking assignments (=) can lead to race conditions and unexpected behavior. Specifically, in your always @(posedge game_clk) block and the always @(comm) block, you use blocking assignments for updating state, point, item_x, item_y, and manipulating map.

Solution:

Use nonblocking assignments (<=) within sequential always blocks to ensure proper timing and avoid race conditions.

Corrections:

• Game Logic Block:

  always @(posedge game_clk) begin
    if (move_dir == 2'b00) Y <= Y + 1;
    else if (move_dir == 2'b01) Y <= Y - 1;
    else if (move_dir == 2'b10) X <= X - 1;
    else if (move_dir == 2'b11) X <= X + 1;
    
    // Update map with the new head position
    map[X][~Y] <= 1'b1;
    
    // Check if the snake has obtained the item
    if (X == item_x && Y == item_y) begin
      if (point > 8'd254) state <= 2'b10; // Use nonblocking assignment
      point <= point + 1'b1;              // Use nonblocking assignment
      
      // Update item position based on movement direction
      if (move_dir == 2'b00 || move_dir == 2'b01) begin
        item_x <= X + 3'b011 + {24'd0, game_clk} * 2; // Ensure correct bit-width
        item_y <= Y - 3'b011 + game_clk;
      end else begin
        item_x <= X - 3'b011 - game_clk;
        item_y <= Y + 3'b011 - game_clk * 2;
      end
    end
    
    // Update snake body
    map[body_mem_x[length - 1]][~body_mem_y[length - 1]] <= 1'b0;
    for (i = 1; i < length; i = i + 1) begin
      body_mem_x[length - i] <= body_mem_x[length - i - 1];
      body_mem_y[length - i] <= body_mem_y[length - i - 1];
    end
    body_mem_x[0] <= X;
    body_mem_y[0] <= Y;
  end
  

• LED Display Block:

  always @(posedge led_clk) begin
    if (comm == 3'b111)
      comm <= 3'b000;
    else
      comm <= comm + 1'b1;
  end
  
  always @(posedge led_clk) begin
    if (state == 2'b10) begin
      LedG <= map[comm];
    end else begin
      LedB <= ~map[comm];
    end
    if (comm == item_x)
      LedR <= ~(1 << item_y); // Turn off the specific LED
    else
      LedR <= 8'b11111111;    // Turn all LEDs on
  end
  

2. Asynchronous Assignments to LEDs in Combinational Block

Issue:

The always @(comm) block is combinational and assigns values to LedR, LedG, and LedB. This can cause glitches and unintended behavior because LedR, LedG, and LedB are also being driven elsewhere.

Solution:

Move LED assignments into a synchronous always block triggered by led_clk to ensure deterministic behavior.

Corrections:

As shown above, combine the LED assignments into the always @(posedge led_clk) block using nonblocking assignments.

3. Initialization of the map Array

Issue:

The map array, which represents the 8x8 LED grid, is not initialized in the initial block. This can lead to undefined behavior since its initial state is unknown.

Solution:

Initialize the map array to a known state (e.g., all zeros) in the initial block.

Corrections:

initial begin
  // Initialize seven-segment display
  // ... [existing initialization code] ...
  
  // Initialize LEDs
  LedR = 8'b11111111;
  LedG = 8'b11111111;
  LedB = 8'b11111111;
  enable = 1'b1;
  comm = 3'b000;
  pass = 1'b0;
  point = 8'b00000000;
  seg = 7'b1111111;
  an = 4'b1110; // Display units digit
  
  // Initialize game state
  X = 3'b010;
  Y = 3'b010;
  length = 6'd3; // Use decimal for clarity
  state = 2'b01;
  move_dir = 2'b00;
  
  // Initialize map to zero
  integer m, n;
  for (m = 0; m < 8; m = m + 1) begin
    map[m] = 8'b00000000;
  end
end

4. Incorrect Handling of the ~Y Indexing

Issue:

Using ~Y for indexing the map array can lead to incorrect row selection because ~Y is a bitwise NOT operation, which inverts all bits of Y. For a 3-bit Y, this results in ~Y = Y ^ 3'b111, effectively mirroring the Y-axis. If this is intentional for mapping purposes, it's acceptable, but it needs to be confirmed.

Solution:

Ensure that using ~Y aligns with your intended mapping. If you want Y=0 to correspond to the top row (7) and Y=7 to the bottom row (0), then ~Y is appropriate. Otherwise, remove the inversion.

Corrections:

If inversion is not intended, change map[X][~Y] to map[X][Y]:

// Without inversion
map[X][Y] <= 1'b1;

// When clearing
map[body_mem_x[length - 1]][body_mem_y[length - 1]] <= 1'b0;

Otherwise, if inversion is intended, ensure it correctly maps to your LED matrix.

5. Incorrect Calculation of item_x and item_y

Issue:

Calculations like item_x = X + 3'b011 + game_clk * 2; involve adding a single bit (game_clk) to a multi-bit value, which can lead to unexpected results due to bit-width mismatches and potential overflows.

Solution:

Ensure that arithmetic operations maintain consistent bit widths and handle potential overflows or underflows, especially since item_x and item_y are 3 bits (values 0 to 7).

Corrections:

Use proper concatenation and bit-width extensions:

// Example correction for item_x and item_y calculations
if (move_dir == 2'b00 || move_dir == 2'b01) begin
  item_x <= X + 3'd3 + (game_clk ? 2'd2 : 3'd0);
  item_y <= Y - 3'd3 + (game_clk ? 1'd1 : 3'd0);
end else begin
  item_x <= X - 3'd3 - game_clk;
  item_y <= Y + 3'd3 - (game_clk ? 2'd2 : 3'd0);
end

Additionally, implement boundary checks to ensure item_x and item_y remain within 0 to 7:

// Boundary check example
always @(posedge game_clk) begin
  // ... [existing game logic] ...
  
  // Ensure item_x and item_y are within 0-7
  if (item_x > 3'd7) item_x <= 3'd7;
  if (item_y > 3'd7) item_y <= 3'd7;
end

6. Seven-Segment Display Displays Binary Value Instead of BCD

Issue:

The point register is an 8-bit binary value, but the seven-segment display expects a Binary-Coded Decimal (BCD) digit. Directly assigning digit = point; and using it to index seg_code will not display the correct decimal digit once point exceeds 9.

Solution:

Convert the binary point value to BCD before displaying it on the seven-segment display. Alternatively, implement a mechanism to display multiple digits.

Corrections:

Implement a simple BCD converter or use additional registers to hold BCD digits:

// Simple BCD conversion (only units digit)
always @(posedge SYS_CLK) begin
  if (RST) begin
    seg <= 7'b1111111;
    an <= 4'b1110;
  end else begin
    // Convert binary point to BCD (units digit only)
    digit <= point % 10; // Note: % operator is not synthesizable; implement binary to BCD conversion
    seg <= seg_code[digit];
    an <= 4'b1110; // Only units digit
  end
end

Note: The modulo operator (%) is not synthesizable in hardware. You'll need to implement a binary-to-BCD conversion algorithm or use a lookup table for BCD digits.

7. Potential Overflow in Counters

Issue:

The move_counter and led_counter have large bit-widths (25 bits) and may lead to excessive resource usage or timing issues.

Solution:

Ensure that the counters' bit-widths are sufficient for the intended maximum counts. Alternatively, adjust the count_to and led_count_to values to match the counters' bit-widths.

Corrections:

If count_to and led_count_to exceed the maximum value representable by 25 bits (33,554,431), adjust accordingly. Otherwise, verify that they align correctly.

8. Unused Registers and Signals

Issue:

Registers like pass and pass_pic are declared but not used anywhere in the code. Unused signals can lead to unnecessary resource consumption.

Solution:

Remove unused registers and signals to optimize the design.

Corrections:

// Remove these declarations if not used
// reg pass;
// reg [7:0] pass_pic [7:0];

9. Missing Collision Detection

Issue:

Currently, the snake can move freely without detecting collisions with walls or itself, which is essential for game functionality.

Solution:

Implement collision detection logic to end the game when the snake collides with the walls or its own body.

Corrections:

Add collision detection in the game logic block:

always @(posedge game_clk) begin
  // ... [existing game logic] ...
  
  // Collision with walls
  if (X >= 3'd8 || Y >= 3'd8) begin
    state <= 2'b10; // End game
  end
  
  // Collision with itself
  integer k;
  for (k = 1; k < length; k = k + 1) begin
    if (body_mem_x[k] == X && body_mem_y[k] == Y) begin
      state <= 2'b10; // End game
    end
  end
  
  // ... [rest of the game logic] ...
end

10. Synchronous vs. Asynchronous Reset

Issue:

Your reset (RST) is handled asynchronously in the seven-segment display logic but not in other parts of the design.

Solution:

Implement a consistent reset strategy across all sequential always blocks to ensure the entire system resets correctly.

Corrections:

Add reset conditions to all relevant always blocks:

// Example for the game clock generation block
always @(posedge SYS_CLK or posedge RST) begin
  if (RST) begin
    move_counter <= 25'd0;
    game_clk <= 1'b0;
    led_counter <= 25'd0;
    led_clk <= 1'b0;
  end else if (PAUSE == 1'b1) begin
    // Do nothing (pause)
  end else begin
    // ... [existing counter logic] ...
  end
end

11. General Code Improvements

• Use Parameters for Constants: Define parameters for constants like led_count_to and count_to for better readability and maintainability.

  parameter LED_COUNT_TO = 5000;
  parameter COUNT_TO = 4500000;
  

• Consistent Bit Widths: Ensure that all arithmetic operations maintain consistent bit widths to prevent unintended truncation or overflows.

• Code Comments and Documentation: Enhance code comments to explain the purpose of each block and the reasoning behind specific implementations. This aids in future debugging and collaboration.

Revised Code Snippet

Here's a revised version of key parts of your code incorporating the corrections mentioned above:

module snakeGameV3(
 output reg [7:0] LedR, LedG, LedB,
 output reg [2:0] comm,
 output reg enable,
 output reg [7:0] point,
 output reg [6:0] seg,  // Seven-segment display output
 output reg [3:0] an,   // Anode select signals
 input SYS_CLK, RST, PAUSE, UP, DOWN, LEFT, RIGHT
);
 
 // Parameters
 parameter LED_COUNT_TO = 5000;
 parameter COUNT_TO = 4500000;
 
 // State Definitions
 localparam GAME = 2'b01;
 localparam END_GAME = 2'b10;
 
 reg [1:0] state;  // GAME or END_GAME
 reg game_clk;
 reg led_clk;
 
 reg [7:0] map [7:0]; // 8x8 LED map[x][y]
 
 reg [2:0] X, Y; // Snake head position
 reg [2:0] body_mem_x[63:0]; // X positions of the body
 reg [2:0] body_mem_y[63:0]; // Y positions of the body
 reg [5:0] length; // Snake length (including head)
 
 reg [2:0] item_x, item_y;
 
 reg [24:0] led_counter;
 reg [24:0] move_counter;
 reg [1:0] move_dir;
 
 reg [3:0] digit; // Decimal digit for seven-segment display
 
 // Seven-segment display codes
 reg [6:0] seg_code [9:0];
 
 integer m, n;
 
 initial begin
  // Initialize seven-segment display codes
  seg_code[0] = 7'b1000000;
  seg_code[1] = 7'b1111001;
  seg_code[2] = 7'b0100100;
  seg_code[3] = 7'b0110000;
  seg_code[4] = 7'b0011001;
  seg_code[5] = 7'b0010010;
  seg_code[6] = 7'b0000010;
  seg_code[7] = 7'b1111000;
  seg_code[8] = 7'b0000000;
  seg_code[9] = 7'b0010000;
  
  // Initialize LEDs to off
  LedR = 8'b11111111;
  LedG = 8'b11111111;
  LedB = 8'b11111111;
  enable = 1'b1;
  comm = 3'b000;
  point = 8'b00000000;
  seg = 7'b1111111;
  an = 4'b1110; // Display units digit
  
  // Initialize game state
  X = 3'b010;
  Y = 3'b010;
  length = 6'd3;
  state = GAME;
  move_dir = 2'b00;
  
  // Initialize map to zero
  for (m = 0; m < 8; m = m + 1) begin
    map[m] = 8'b00000000;
  end
end
 
// Seven-segment display logic
always @(posedge SYS_CLK or posedge RST) begin
  if (RST) begin
    seg <= 7'b1111111;
    an <= 4'b1110;
  end else begin
    // Simple binary to BCD conversion for units digit
    digit <= point % 10; // Implement a proper BCD conversion as needed
    seg <= seg_code[digit];
    an <= 4'b1110; // Only units digit
  end
end
 
// Clock generation for game and LED updates
always @(posedge SYS_CLK or posedge RST) begin
  if (RST) begin
    move_counter <= 25'd0;
    game_clk <= 1'b0;
    led_counter <= 25'd0;
    led_clk <= 1'b0;
  end else if (PAUSE) begin
    // Do nothing (pause)
  end else begin
    // Update move counter
    if (move_counter < COUNT_TO - 1) begin
      move_counter <= move_counter + 1;
    end else begin
      game_clk <= ~game_clk;
      move_counter <= 25'd0;
    end
    
    // Update LED counter
    if (led_counter < LED_COUNT_TO - 1) begin
      led_counter <= led_counter + 1;
    end else begin
      led_clk <= ~led_clk;
      led_counter <= 25'd0;
    end
  end
end
 
// LED display logic
always @(posedge led_clk or posedge RST) begin
  if (RST) begin
    comm <= 3'b000;
    LedR <= 8'b11111111;
    LedG <= 8'b11111111;
    LedB <= 8'b11111111;
  end else begin
    // Update communication signal
    if (comm == 3'b111)
      comm <= 3'b000;
    else
      comm <= comm + 1'b1;
    
    // Update LED colors based on state
    if (state == END_GAME) begin
      LedG <= map[comm];
      LedB <= 8'b11111111; // Turn off Blue LEDs
    end else begin
      LedB <= ~map[comm];
      LedG <= 8'b11111111; // Turn off Green LEDs
    end
    
    // Update Red LEDs for item
    if (comm == item_x)
      LedR <= ~(1 << item_y); // Turn off specific LED
    else
      LedR <= 8'b11111111;    // Turn all Red LEDs on
  end
end
 
// Update movement direction based on input
always @(posedge SYS_CLK or posedge RST) begin
  if (RST) begin
    move_dir <= 2'b00;
  end else begin
    if (UP && !DOWN && !LEFT && !RIGHT && move_dir != 2'b01)
      move_dir <= 2'b00;
    else if (DOWN && !UP && !LEFT && !RIGHT && move_dir != 2'b00)
      move_dir <= 2'b01;
    else if (LEFT && !UP && !DOWN && !RIGHT && move_dir != 2'b11)
      move_dir <= 2'b10;
    else if (RIGHT && !UP && !DOWN && !LEFT && move_dir != 2'b10)
      move_dir <= 2'b11;
  end
end
 
// Game main logic
always @(posedge game_clk or posedge RST) begin
  if (RST) begin
    // Reset game state
    X <= 3'b010;
    Y <= 3'b010;
    length <= 6'd3;
    state <= GAME;
    point <= 8'd0;
    // Reset map and body positions
    for (m = 0; m < 8; m = m + 1) begin
      map[m] <= 8'b00000000;
    end
    for (n = 0; n < 64; n = n + 1) begin
      body_mem_x[n] <= 3'd0;
      body_mem_y[n] <= 3'd0;
    end
    // Initialize first body segments
    body_mem_x[0] <= X;
    body_mem_y[0] <= Y;
    body_mem_x[1] <= X;
    body_mem_y[1] <= Y;
    body_mem_x[2] <= X;
    body_mem_y[2] <= Y;
    // Initialize item position
    item_x <= X + 3'd3;
    item_y <= Y + 3'd3;
  end else begin
    if (state == GAME) begin
      // Update snake position based on direction
      case (move_dir)
        2'b00: Y <= Y + 1;
        2'b01: Y <= Y - 1;
        2'b10: X <= X - 1;
        2'b11: X <= X + 1;
      endcase
      
      // Update map with new head position
      map[X][Y] <= 1'b1;
      
      // Check if snake has obtained the item
      if (X == item_x && Y == item_y) begin
        if (point >= 8'd254) begin
          state <= END_GAME;
        end else begin
          point <= point + 1;
          // Update item position (ensure within bounds)
          case (move_dir)
            2'b00, 2'b01: begin
              item_x <= (X + 3'd3 + (game_clk ? 3'd2 : 3'd0)) % 8;
              item_y <= (Y - 3'd3 + (game_clk ? 3'd1 : 3'd0)) % 8;
            end
            2'b10, 2'b11: begin
              item_x <= (X - 3'd3 - game_clk) < 3'd0 ? 3'd0 : (X - 3'd3 - game_clk);
              item_y <= (Y + 3'd3 - (game_clk ? 3'd2 : 3'd0)) % 8;
            end
          endcase
        end
      end
      
      // Update snake body
      map[body_mem_x[length - 1]][body_mem_y[length - 1]] <= 1'b0;
      for (i = 1; i < length; i = i + 1) begin
        body_mem_x[length - i] <= body_mem_x[length - i - 1];
        body_mem_y[length - i] <= body_mem_y[length - i - 1];
      end
      body_mem_x[0] <= X;
      body_mem_y[0] <= Y;
      
      // Collision Detection
      if (X >= 3'd8 || Y >= 3'd8) begin
        state <= END_GAME;
      end
      
      integer k;
      for (k = 1; k < length; k = k + 1) begin
        if (body_mem_x[k] == X && body_mem_y[k] == Y) begin
          state <= END_GAME;
        end
      end
    end
  end
end

endmodule

Summary of Key Fixes:

1. Use Nonblocking Assignments (<=) in Sequential Blocks: This ensures proper timing and avoids race conditions.
2. Initialize All Registers and Arrays: Prevents undefined behavior by setting initial states.
3. Synchronous LED Updates: Move LED assignments into synchronous blocks to maintain deterministic behavior.
4. Proper Handling of item_x and item_y: Ensure arithmetic operations account for bit-widths and boundaries.
5. Implement Collision Detection: Enhances game functionality by ending the game on collisions.
6. Convert Binary to BCD for Seven-Segment Display: Ensures correct numerical representation on the display.
7. Consistent Reset Handling: Applies reset conditions uniformly across all parts of the design.

By addressing these issues, your snakeGameV3 module should function more reliably and as intended. Be sure to thoroughly simulate and test the revised code to verify its behavior before deploying it to hardware.

解决编译错误

我正在修复自己编写的蛇形游戏Verilog模块的编译错误。看起来在第241行遇到了语法错误，可能是由于缺失了"end"关键字。

解剖错误

检查代码块是否完整，是否有多余的关键字。分析语法错误，探讨可能的原因，排除脆弱点。

捕捉代码错位

注意到主游戏逻辑块中的'for'循环和'end'，以及模块关闭的"endmodule"。语法错误可能源于未闭合的'begin'和'optional end'。

梳理代码细节

关注'array[x][~y]'的改动及可能的语法错误。修正'begin'/'end'对、变量声明和整数使用，确保模块关闭和警告处理。

解决语法问题

在'always @(posedge game_clk or posedge RST)'块中，'integer k;'声明可能导致错误。查看代码是否有缺失的'begin'/'end'对，可能需要修正。

检查代码结构

我正在审视主游戏逻辑块，确保每个'begin'都有对应的'end'。也在确认模块结尾是否缺失了"endmodule"。

修正代码细节

我正在确保每个'begin'都有'end'，并且将整数变量声明放在'always'块的开始部分。这样可以防止编译器困惑于'integer'关键字的位置问题。

检查内部结构

我正在仔细检查'allways'块中的'begin'和'end'，确保闭合正确。特别注意状态为GAME时的'for'循环及其内部逻辑。

检查闭合匹配

调整'for'循环的'begin'和'end'闭合，使用缩进来可视化嵌套关系。确保所有循环都有对应的'end'，并验证数组的语法。

清晰定义范围

检查X和Y的位数，确保不超过3位的值。修改比较运算以避免不必要的条件判断。检查以上内容是否导致错误。

检查范围定义

修改比较运算，将'X >= 3'd8'改为'X >= 3'd7'，确保逻辑正确并避免语法错误。

修复语法错误

修正语法错误，特别是第241行的'integer'问题，调整比较字面值，并确保'always'块内部的'begin'/'end'配对正确。

调整代码块结构

检查Verilog语法，确保'allways'块中的整数变量声明放在块的开始部分，以防语法错误。

调整变量声明

我正在仔细检查Verilog代码，确保在'always'块之前声明所有变变量，以避免语法错误。这样可以确保代码的正确性。

重新调整位置

我在'always'块内将'integer k;'移动到了'before any statements'之前。这样做解决了语法错误。

经验讨论解决方案

将'X >= 3'd8'修改为'X == 3'd7'，而'X < 3'd0'替换为'X == 3'd0'。同样适用于'Y'。

思考 花的時間為 24 秒

The errors you're encountering are primarily due to syntax issues in your Verilog code. Let's address each error and warning step-by-step to help you resolve them.

1. Syntax Error: Expecting "end" Near "integer"

Error Details:

Error (10170): Verilog HDL syntax error at snakeGameV3.v(241) near text "integer";  expecting "end"

Cause:

In Verilog, all variable declarations within an always block must be placed before any executable statements. If you declare an integer (or any other variable) after starting executable statements (like if, for, etc.), the compiler will throw a syntax error expecting an end to close the previous block.

In your revised code, it's likely that integer declarations inside always blocks are placed after some executable statements, causing the compiler to misinterpret the structure.

Solution:

Move all integer declarations to the beginning of their respective always blocks, before any if, for, or other executable statements.

Corrections:

Here's how you can adjust your always blocks to ensure proper syntax:

a. Game Main Logic Block:

Before Correction:

always @(posedge game_clk or posedge RST) begin
  if (RST) begin
    // Reset logic
  end else begin
    if (state == GAME) begin
      // Game logic
      
      // Collision Detection
      integer k;
      for (k = 1; k < length; k = k + 1) begin
        if (body_mem_x[k] == X && body_mem_y[k] == Y) begin
          state <= END_GAME;
        end
      end
      
      // Rest of the game logic
    end
  end
end

After Correction:

always @(posedge game_clk or posedge RST) begin
  integer k; // Move declaration to the beginning
  if (RST) begin
    // Reset logic
  end else begin
    if (state == GAME) begin
      // Game logic
      
      // Collision Detection
      for (k = 1; k < length; k = k + 1) begin
        if (body_mem_x[k] == X && body_mem_y[k] == Y) begin
          state <= END_GAME;
        end
      end
      
      // Rest of the game logic
    end
  end
end

b. Initial Block:

Ensure that all declarations inside the initial block are correctly placed. Typically, integer declarations are placed outside initial blocks, but if needed inside, they should also be at the beginning.

Example:

initial begin
  integer m, n; // Declare loop variables at the beginning
  // Initialize seven-segment display codes
  // Initialize LEDs
  // Initialize game state
  // Initialize map
end

2. Warning: Truncated Literal to Match Bit Width

Warning Details:

Warning (10229): Verilog HDL Expression warning at snakeGameV3.v(237): truncated literal to match 3 bits

Cause:

You are comparing a 3-bit signal (X or Y) to a 3-bit literal 3'd8. However, 3'd8 requires at least 4 bits to represent the value 8 (binary 1000). Since X and Y are only 3 bits wide, the literal 3'd8 gets truncated to 3'd0, leading to unintended behavior.

Solution:

Adjust the comparison literals to fit within the 3-bit width of X and Y. Since 3 bits can represent values from 0 to 7, you should compare against 3'd7 instead of 3'd8. Additionally, since X and Y cannot exceed 7, you should adjust your collision detection logic accordingly.

Corrections:

a. Collision Detection:

Before Correction:

// Collision with walls
if (X >= 3'd8 || Y >= 3'd8) begin
  state <= END_GAME; // End game
end

After Correction:

// Collision with walls (assuming 0 and 7 are the boundaries)
if (X == 3'd0 || X == 3'd7 || Y == 3'd0 || Y == 3'd7) begin
  state <= END_GAME; // End game
end

b. Update Item Position Logic:

Ensure that any arithmetic operations do not result in values outside the 3-bit range. Implement boundary checks or use modulo operations to wrap around if necessary.

Example Correction:

// Update item position (ensure within bounds)
if (move_dir == 2'b00 || move_dir == 2'b01) begin
  item_x <= (X + 3'd3 + (game_clk ? 3'd2 : 3'd0)) % 3'd8;
  item_y <= (Y - 3'd3 + (game_clk ? 3'd1 : 3'd0)) % 3'd8;
end else begin
  item_x <= (X - 3'd3 - game_clk) < 3'd0 ? 3'd0 : (X - 3'd3 - game_clk);
  item_y <= (Y + 3'd3 - (game_clk ? 3'd2 : 3'd0)) % 3'd8;
end

Note: The modulo operator % is not synthesizable in standard Verilog. You may need to implement conditional logic to handle wrapping or boundary conditions.

3. Comprehensive Corrected Code

To ensure clarity and correctness, here's the fully corrected version of your snakeGameV3 module incorporating all the fixes:

module snakeGameV3(
  output reg [7:0] LedR, LedG, LedB,
  output reg [2:0] comm,
  output reg enable,
  output reg [7:0] point,
  output reg [6:0] seg,  // Seven-segment display output
  output reg [3:0] an,   // Anode select signals
  input SYS_CLK, RST, PAUSE, UP, DOWN, LEFT, RIGHT
);
  
  // Parameters
  parameter LED_COUNT_TO = 5000;
  parameter COUNT_TO = 4500000;
  
  // State Definitions
  localparam GAME = 2'b01;
  localparam END_GAME = 2'b10;
  
  reg [1:0] state;  // GAME or END_GAME
  reg game_clk;
  reg led_clk;
  
  reg [7:0] map [7:0]; // 8x8 LED map[x][y]
  
  reg [2:0] X, Y; // Snake head position
  reg [2:0] body_mem_x[63:0]; // X positions of the body
  reg [2:0] body_mem_y[63:0]; // Y positions of the body
  reg [5:0] length; // Snake length (including head)
  
  reg [2:0] item_x, item_y;
  
  reg [24:0] led_counter;
  reg [24:0] move_counter;
  reg [1:0] move_dir;
  
  reg [3:0] digit; // Decimal digit for seven-segment display
  
  // Seven-segment display codes
  reg [6:0] seg_code [9:0];
  
  integer m, n;
  
  initial begin
    // Initialize seven-segment display codes
    seg_code[0] = 7'b1000000;
    seg_code[1] = 7'b1111001;
    seg_code[2] = 7'b0100100;
    seg_code[3] = 7'b0110000;
    seg_code[4] = 7'b0011001;
    seg_code[5] = 7'b0010010;
    seg_code[6] = 7'b0000010;
    seg_code[7] = 7'b1111000;
    seg_code[8] = 7'b0000000;
    seg_code[9] = 7'b0010000;
    
    // Initialize LEDs to off
    LedR = 8'b11111111;
    LedG = 8'b11111111;
    LedB = 8'b11111111;
    enable = 1'b1;
    comm = 3'b000;
    point = 8'b00000000;
    seg = 7'b1111111;
    an = 4'b1110; // Display units digit
    
    // Initialize game state
    X = 3'b010;
    Y = 3'b010;
    length = 6'd3;
    state = GAME;
    move_dir = 2'b00;
    
    // Initialize map to zero
    for (m = 0; m < 8; m = m + 1) begin
      map[m] = 8'b00000000;
    end
    
    // Initialize snake body positions
    for (n = 0; n < length; n = n + 1) begin
      body_mem_x[n] = X;
      body_mem_y[n] = Y;
    end
    
    // Initialize item position
    item_x = X + 3'd3;
    item_y = Y + 3'd3;
  end
  
  // Seven-segment display logic
  always @(posedge SYS_CLK or posedge RST) begin
    if (RST) begin
      seg <= 7'b1111111;
      an <= 4'b1110;
    end else begin
      // Simple binary to BCD conversion for units digit
      // Note: % operator is not synthesizable. Implement proper BCD conversion.
      // Here, we'll limit point to 9 for simplicity.
      if (point > 8'd9) begin
        digit <= 4'd0; // Reset or handle overflow as needed
      end else begin
        digit <= point[3:0];
      end
      seg <= seg_code[digit];
      an <= 4'b1110; // Only units digit
    end
  end
  
  // Clock generation for game and LED updates
  always @(posedge SYS_CLK or posedge RST) begin
    if (RST) begin
      move_counter <= 25'd0;
      game_clk <= 1'b0;
      led_counter <= 25'd0;
      led_clk <= 1'b0;
    end else if (PAUSE) begin
      // Do nothing (pause)
    end else begin
      // Update move counter
      if (move_counter < COUNT_TO - 1) begin
        move_counter <= move_counter + 1;
      end else begin
        game_clk <= ~game_clk;
        move_counter <= 25'd0;
      end
      
      // Update LED counter
      if (led_counter < LED_COUNT_TO - 1) begin
        led_counter <= led_counter + 1;
      end else begin
        led_clk <= ~led_clk;
        led_counter <= 25'd0;
      end
    end
  end
  
  // LED display logic
  always @(posedge led_clk or posedge RST) begin
    if (RST) begin
      comm <= 3'b000;
      LedR <= 8'b11111111;
      LedG <= 8'b11111111;
      LedB <= 8'b11111111;
    end else begin
      // Update communication signal
      if (comm == 3'b111)
        comm <= 3'b000;
      else
        comm <= comm + 1'b1;
      
      // Update LED colors based on state
      if (state == END_GAME) begin
        LedG <= map[comm];
        LedB <= 8'b11111111; // Turn off Blue LEDs
      end else begin
        LedB <= ~map[comm];
        LedG <= 8'b11111111; // Turn off Green LEDs
      end
      
      // Update Red LEDs for item
      if (comm == item_x)
        LedR <= ~(1 << item_y); // Turn off specific LED
      else
        LedR <= 8'b11111111;    // Turn all Red LEDs on
    end
  end
  
  // Update movement direction based on input
  always @(posedge SYS_CLK or posedge RST) begin
    if (RST) begin
      move_dir <= 2'b00;
    end else begin
      if (UP && !DOWN && !LEFT && !RIGHT && move_dir != 2'b01)
        move_dir <= 2'b00;
      else if (DOWN && !UP && !LEFT && !RIGHT && move_dir != 2'b00)
        move_dir <= 2'b01;
      else if (LEFT && !UP && !DOWN && !RIGHT && move_dir != 2'b11)
        move_dir <= 2'b10;
      else if (RIGHT && !UP && !DOWN && !LEFT && move_dir != 2'b10)
        move_dir <= 2'b11;
    end
  end
  
  // Game main logic
  always @(posedge game_clk or posedge RST) begin
    integer k; // Declare at the beginning of the block
    if (RST) begin
      // Reset game state
      X <= 3'b010;
      Y <= 3'b010;
      length <= 6'd3;
      state <= GAME;
      point <= 8'd0;
      
      // Reset map
      for (m = 0; m < 8; m = m + 1) begin
        map[m] <= 8'b00000000;
      end
      
      // Reset snake body positions
      for (n = 0; n < length; n = n + 1) begin
        body_mem_x[n] <= X;
        body_mem_y[n] <= Y;
      end
      
      // Reset item position
      item_x <= X + 3'd3;
      item_y <= Y + 3'd3;
    end else if (state == GAME) begin
      // Update snake position based on direction
      case (move_dir)
        2'b00: Y <= Y + 1;
        2'b01: Y <= Y - 1;
        2'b10: X <= X - 1;
        2'b11: X <= X + 1;
      endcase
      
      // Update map with new head position
      map[X][Y] <= 1'b1;
      
      // Check if snake has obtained the item
      if (X == item_x && Y == item_y) begin
        if (point >= 8'd254) begin
          state <= END_GAME;
        end else begin
          point <= point + 1;
          // Update item position based on movement direction
          if (move_dir == 2'b00 || move_dir == 2'b01) begin
            // Ensure item_x and item_y stay within 0-7
            item_x <= (X + 3'd3 + 3'd2) % 3'd8;
            item_y <= (Y - 3'd3 + 3'd1) % 3'd8;
          end else begin
            item_x <= (X - 3'd3 - 1'd1) < 3'd0 ? 3'd0 : (X - 3'd3 - 1'd1);
            item_y <= (Y + 3'd3 - 3'd2) % 3'd8;
          end
        end
      end
      
      // Update snake body
      map[body_mem_x[length - 1]][body_mem_y[length - 1]] <= 1'b0;
      for (k = 1; k < length; k = k + 1) begin
        body_mem_x[length - k] <= body_mem_x[length - k - 1];
        body_mem_y[length - k] <= body_mem_y[length - k - 1];
      end
      body_mem_x[0] <= X;
      body_mem_y[0] <= Y;
      
      // Collision Detection with walls
      if (X == 3'd0 || X == 3'd7 || Y == 3'd0 || Y == 3'd7) begin
        state <= END_GAME;
      end
      
      // Collision Detection with itself
      for (k = 1; k < length; k = k + 1) begin
        if (body_mem_x[k] == X && body_mem_y[k] == Y) begin
          state <= END_GAME;
        end
      end
    end
  end
  
endmodule

4. Additional Recommendations

a. Binary to BCD Conversion:

The current implementation for the seven-segment display only handles the units digit and does not perform an actual Binary to BCD (Binary-Coded Decimal) conversion. The modulo operation (%) is not synthesizable in standard Verilog. To display multiple digits or perform proper BCD conversion, consider implementing a BCD conversion algorithm or using separate counters for each digit.

b. Handling Overflows:

Ensure that the point register does not overflow beyond its maximum value (8'd255). Implement logic to handle cases where point exceeds this value, such as resetting the score or stopping the game.

c. Boundary Conditions:

Ensure that all arithmetic operations on X, Y, item_x, and item_y stay within the 0-7 range. You might need to implement additional checks or use unsigned arithmetic to prevent underflows or overflows.

d. Modular Design:

Consider breaking down your code into smaller modules (e.g., separate modules for display control, game logic, input handling) to improve readability and maintainability.

e. Simulation and Testing:

Before synthesizing the code with Quartus, simulate it using a tool like ModelSim to verify its behavior. This can help identify logical errors that might not be caught during synthesis.

5. Summary of Fixes

1. Moved integer Declarations:

   • All integer declarations inside always blocks are now at the beginning of the begin block to adhere to Verilog syntax rules.

2. Adjusted Comparison Literals:

   • Changed comparisons from 3'd8 to appropriate values within the 3-bit range (0-7). For example, X >= 3'd8 is replaced with X == 3'd7 or appropriate logic.

3. Ensured Proper begin/end Pairing:

   • Verified that every begin has a corresponding end to prevent the compiler from expecting additional end statements.

4. Handled Seven-Segment Display Limitation:

   • Limited the digit to display values between 0-9 to match the seven-segment display capabilities.

5. Implemented Boundary Checks:

   • Added logic to prevent item_x and item_y from exceeding the 0-7 range.

By implementing these corrections, your snakeGameV3 module should compile successfully in Quartus II without syntax errors. Make sure to thoroughly test the module through simulation to verify that the game logic behaves as expected.

If you encounter further issues or have additional questions, feel free to ask!

Adjusting the color scheme

The entire map is green at the start of the game. The user likely wants a different initial color or combination, needing debugging or code modification.

Assessing color logic

IF (state == 2'b10) THEN LEDs show green else blue. Green at game start suggests the state might default to 2'b10, potentially due to code errors.

Clarifying initial conditions

I'm working through why the map is green at game start. The issue might be the map defaulting to all ones, leading to LEDs showing off based on hardware setup.

Assessing the likelihood

OK, let me see. If the map is all 1s and the hardware is active low, the LEDs might be off, causing the map to look green. This fits with the given state.

Assessing initial colors

I’m mapping out if code adjustments for "comm" or "led_clk" might affect initial LED states. The map's zero-initialization and state settings seem key to avoiding the all-green appearance.

Analyzing active low LEDs

Hm, that's interesting. If the board uses active low LEDs and LedG = 8'b00000000, the LEDs might light up. To turn them off or manage their state, inverting could help.

Toggling LED states

To manage the active low LEDs, the user should invert the logic for the green assignment. This approach should help in achieving the desired LED states effectively.

Adjusting LED logic

Inverting the green assignment or setting the map to all 1s (active low setup) should fix the initial green LEDs issue. Ensuring these adjustments should solve the problem.

Thought about game map initialization 花的時間為 16 秒

以下討論的重點在於：「為什麼遊戲一開始 8x8 LED 矩陣全都亮起綠燈」(或看起來像是全綠)，以及該如何修正。這通常與以下幾個因素有關：

1. LED 硬體的「主動低 (active-low)」或「主動高 (active-high)」設計
2. Verilog 內對 map 的初始化值 (0 或 1) 與實際想顯示「亮/滅」之間的關係
3. 狀態 (state) 與顯示邏輯的 if-else 條件
4. 實際上 LedG, LedB, LedR 對硬體的輸出「0」是亮燈還是熄燈

以下分步說明可能的原因與對應解法。

1. 硬體預設是「低電位點亮 LED」還是「高電位點亮 LED」

很多 FPGA 開發板(或 LED Driver) 的 8x8 矩陣，LED 都是主動低(active-low)。

• 主動低：如果輸出腳位是 0，則該 LED 亮；如果是 1，則該 LED 熄。
• 主動高：如果輸出腳位是 1，則該 LED 亮；如果是 0，則該 LED 熄。

若你的開發板是主動低，但程式中將 map[x][y] = 1'b1 當作「亮燈」，在實際硬體上就變成「熄燈」。反之，如果 map[x][y] = 0 表示「滅」，但硬體上卻是「亮」。
所以一開始若程式碼把 map[m] 初始化為 8'b00000000，等同於輸出都是 0，對於主動低硬體來說就是「全部亮」——這就解釋了遊戲開始時地圖全是綠的情況。

解法：調整顯示反相 (invert)

假設你要在「遊戲中 (state == 2'b01)」顯示藍色時，使用

LedB = ~map[comm]; 

那麼 map[comm] = 0 時，~map[comm] = 8'b11111111，表示LED 熄滅(若硬體是主動低)。
相反地，如果你只是寫

LedB = map[comm];

那麼 map[comm] = 0 時，輸出腳位就會是 0，主動低硬體就會把該列 LED 全亮。

所以如果想一開始地圖全暗

• 可以把 map[m] 初始化為 8'b00000000，然後輸出端要使用反相 ~map[comm]。
  • 如此一來，0 表示「要熄燈」，對硬體輸出就會是 1，實體就「不亮」。
• 或者，你也可以把 map[m] 初始化為 8'b11111111，然後輸出端 不 做反相 LedB = map[comm]；如此一來 1 表示「要熄燈」，硬體看到 1 就熄燈。

兩種邏輯只要「程式端的定義」和「硬體實際」是一致的，就能達到你想要的顯示結果。

2. 確認 state 是否真的在「遊戲進行」(2'b01) 而非「結束」(2'b10)

在程式碼中常見類似：

if (state == 2'b10) begin
  LedG = map[comm]; // 結束狀態顯示綠色
end else begin
  LedB = ~map[comm]; // 遊戲進行時顯示藍色(反相)
end

若你一開始的 initial 區塊裏面是：

initial begin
  state = 2'b01; // 遊戲進行
  ...
end

理論上進來應該執行 LedB = ~map[comm]; 而非 LedG = map[comm];。
若你實際硬體上卻看到全綠，很可能有以下原因：

1. initial 區塊沒執行預期的動作：有些綜合器或模擬器對多維陣列或過度複雜的初始動作處理有限制。
2. 在某處意外把 state 改成了 2'b10：可能程式某一行有 bug，提早進入遊戲結束狀態。
3. 顏色腳位與電路接法跟程式期待不符：也有可能硬體腳位對應錯了。

檢查方式：

• 模擬 (simulation) 先看 state 初始值是否真的是 2'b01。
• 在真實 FPGA 上可以用信號探針 (SignalTap) 或 Debug LED 顯示 state 是否真的停在 2'b01。
• 若發現根本一直是 2'b10，代表前面程式流程可能馬上就偵測到「撞牆」或「自身碰撞」等條件，而切換到結束狀態。

3. 如何讓「地圖」在遊戲開始時是「全暗 (不亮)」

常見做法有兩種：

方法 A: 保持 map = 0，輸出端做反相

1. 在 initial 裏面：

   for (m = 0; m < 8; m = m + 1) begin
     map[m] = 8'b00000000; // 全部設為0
   end
   

2. 在顯示邏輯：

   if (state == 2'b10) begin
     // 結束狀態用綠色
     LedG = ~map[comm];
     // 如果硬體是主動低，這樣 map=0 => LedG= 8'hFF => 全熄
     // map=1 => LedG= 8'hFE => 亮某個點
   end else begin
     // 遊戲進行時用藍色
     LedB = ~map[comm];
   end
   

   也就是永遠輸出 ~map[comm]，0 就亮，1 就熄。如果你想讓 0 是暗、1 是亮，就反過來即可。

方法 B: 保持 map = 1，輸出端不反相

1. 在 initial 裏面：

   for (m = 0; m < 8; m = m + 1) begin
     map[m] = 8'b11111111; // 全部設為1
   end
   

2. 在顯示邏輯：

   if (state == 2'b10) begin
     LedG = map[comm]; 
   end else begin
     LedB = map[comm];
   end
   

   如果硬體是主動低，map[comm] = 1 就會輸出腳位=1 => LED 不亮。

4. 若真想「一開始只有蛇身或某些位置亮」

1. 先把 map 全部清空(或全部設為 1，看你想讓 0/1 代表什麼)。
2. 再把蛇頭和身體所在的位置對應設定為亮：

   // 假設你用 map[X][Y] = 1 表示要亮
   map[init_snake_head_x][init_snake_head_y] = 1;
   map[init_snake_body_x1][init_snake_body_y1] = 1;
   ...
   

3. item (果實) 的位置若在開始就生成，也相對在 map 那個位置設為 1 (或 0)，以達到對應顯示。

5. 總結 Debug 流程

1. 檢查 state 初始值
   • 確定是 2'b01(遊戲進行)，不要誤設為 2'b10(結束)。
2. 檢查硬體是否主動低
   • 如果是主動低，輸出 0 代表「點亮 LED」，輸出 1 代表「熄滅 LED」；所以需要在程式邏輯中做 ~ (反相) 或改變 map 初始化。
3. 檢查 map 初始化
   • 如果你想「地圖全暗」，而硬體又是主動低，則 map = 8'b00000000 + Led = ~map[comm]；或 map = 8'b11111111 + Led = map[comm]。
4. 檢查蛇一開始有沒有立刻撞牆
   • 如果蛇的初始座標在地圖邊界外或馬上偵測到碰撞，程式會進入 END_GAME，導致全綠。
5. 實際看波形 (Simulation / SignalTap)
   • 最準確的方法是跑模擬 (ModelSim, Riviera-PRO, etc.)，或用 SignalTap 抓 FPGA 內部變數，確認程式走到哪裡、各變數值是什麼。

結論：遊戲開始時地圖都是綠色，通常是因為：

• (A) 程式其實一開始就跑到結束狀態 state == 2'b10，因此全部用 LedG 亮。
• (B) 或者是 map / LED 邏輯上的「0 → LED 亮」對應關係跟你想像相反，導致你看到的其實是「全部亮着」，而顯示顏色正好是在 LedG。

解法重點：

1. 先確認硬體是「主動低」還是「主動高」。
2. 再決定 map 裏面要放 0 還是 1，對應「亮燈 / 熄燈」。
3. 若想一開始全部暗，那就保證初始化與輸出端的對應方向一致。
4. 確保 state 沒被誤判成遊戲結束。

只要把這些調整好，就可以讓遊戲一開始不是整片綠色，而是你預期的顯示狀態。祝 Debug 順利!

修复代码错误

用户指示有两个Verilog代码错误。第一是忽略了"sankGameV3"的设计单元。第二是在241行附近的Verilog HDL语法错误。

分析错误和警告

我发现此问题可能由Verilog语言在"always"代码块中声明"integer"变量放置不当引起，或由于位宽不匹配导致字面量截断。

探讨错误原因

用户指出硬件LED的主动高和主动低特性，并建议初始化地图。现在，用户正在解决Verilog代码中的错误。

排查代码问题

由于Verilog语言的语法范围在0到255之间，以及模块名和设计单元名匹配问题，都可能导致编译错误。

改正Verilog代码

我需要修改Verilog代码，确保所有'snakeGameV3'模块的'integer'声明位于'always'块的开头，解决地图初始化和LED逻辑问题。

调整和优化

修正Verilog代码中的语法错误，确保'integer'声明位于'always'块的开头，解决地图初始化和LED逻辑问题。提供详细修复说明和更正后的代码。

仔细探讨

我纠正Verilog代码中的语法错误，确保'integer'声明放在'always'块的开头，处理位宽不匹配和地图初始化问题，并验证模块语法的正确性。

分析旧代码

我正在审视旧代码，试图发现潜在问题，确保相关变量使用一致的位宽和用途，避免因变量尺寸不匹配而引发错误。

审查与纠正

对Verilog代码进行详细审查，纠正语法错误，确保'integer'声明位于'always'块之上，处理位宽不匹配和地图初始化问题，并验证模块语法的正确性。

纠正声明位置

修正Verilog代码，将所有'integer'声明放在'always'块的顶部，确保变量声明符合Verilog的标准。

修復指導

幫助用戶修正Verilog代碼，確保'integer'聲明位於'always'塊的開頭，修正所有'3'd8'問題，並且不要讓初始的LED綠色燈全亮。

完善Verilog代码

整理Verilog代码，确保'integer'声明位于'always'块的开头，修正3'd8的问题，替换为3位值，且考虑活跃低的LED初始化和地图分配。

调整Verilog代码

在项的'始且，'始和活跃性低的LED初始化','映΃ asdasd

探讨LED活性问题
让我们看看如何解决活性低的LED初始化问题，以确保'map'正确初始化。 خطةאַקasaa

调整Verilog代码

我已经纠正了Verilog代码，确保'integer'声明位于'always'块的开头，修正了3'd8问题，现在正在处理活跃低的LED初始化和地图分配，同时避免初始LED亮起。

细化步骤和增量

我已经分步处理课程内容，涵盖数据类型、运算符、流程控制和数组使用。通过讲解关键概念和典型例子，确保理解并创作实际问题解决方法。

调整Verilog代码

我已经调整了Verilog代码，确保'integer'声明位于'always'块的开头，修正了3'd8问题，同时解决了活跃低的LED初始化和地图分配问题。

思考 花的時間為 38 秒

了解您在 Quartus 編譯時遇到的問題，特別是關於 Verilog 語法錯誤和 LED 顯示問題。我將提供一個修正過的完整 snakeGameV3 模組，並詳細說明所做的修正，以確保程式能夠順利編譯並在硬體上正常運行。

修正後的 Verilog 程式碼

module snakeGameV3(
  output reg [7:0] LedR, LedG, LedB,
  output reg [2:0] comm,
  output reg enable,
  output reg [7:0] point,
  output reg [6:0] seg,  // 七段顯示器輸出
  output reg [3:0] an,   // 位選訊號
  input SYS_CLK, RST, PAUSE, UP, DOWN, LEFT, RIGHT
);
  
  // 參數定義
  parameter LED_COUNT_TO = 5000;
  parameter COUNT_TO = 4500000;
  
  // 狀態定義
  localparam GAME = 2'b01;
  localparam END_GAME = 2'b10;
  
  reg [1:0] state;  // GAME 或 END_GAME
  reg game_clk;
  reg led_clk;
  
  reg [7:0] map [7:0]; // 8x8 LED 地圖 map[x][y]
  
  reg [2:0] X, Y; // 蛇頭位置
  reg [2:0] body_mem_x [63:0]; // 蛇身的 X 位置
  reg [2:0] body_mem_y [63:0]; // 蛇身的 Y 位置
  reg [5:0] length; // 蛇的長度（包含頭）
  
  reg [2:0] item_x, item_y; // 物品位置
  
  reg [24:0] led_counter;
  reg [24:0] move_counter;
  reg [1:0] move_dir;
  
  reg [3:0] digit; // 七段顯示器的數字
  
  // 七段顯示器數字對應的位元碼
  reg [6:0] seg_code [9:0];
  
  integer m, n; // 迴圈變數
  
  initial begin
    // 初始化七段顯示器數字對應表
    seg_code[0] = 7'b1000000; // 0
    seg_code[1] = 7'b1111001; // 1
    seg_code[2] = 7'b0100100; // 2
    seg_code[3] = 7'b0110000; // 3
    seg_code[4] = 7'b0011001; // 4
    seg_code[5] = 7'b0010010; // 5
    seg_code[6] = 7'b0000010; // 6
    seg_code[7] = 7'b1111000; // 7
    seg_code[8] = 7'b0000000; // 8
    seg_code[9] = 7'b0010000; // 9
    
    // 初始化 LED（假設主動低，1 表示熄滅，0 表示點亮）
    LedR = 8'b11111111;
    LedG = 8'b11111111;
    LedB = 8'b11111111;
    enable = 1'b1;
    comm = 3'b000;
    point = 8'b00000000;
    seg = 7'b1111111;
    an = 4'b1110; // 預設顯示個位數
    
    // 初始化遊戲狀態
    X = 3'b010;
    Y = 3'b010;
    length = 6'd3;
    state = GAME;
    move_dir = 2'b00;
    
    // 初始化地圖為全熄滅（主動低）
    for (m = 0; m < 8; m = m + 1) begin
      map[m] = 8'b11111111; // 1 表示熄滅
    end
    
    // 初始化蛇身位置
    for (n = 0; n < length; n = n + 1) begin
      body_mem_x[n] = X;
      body_mem_y[n] = Y;
    end
    
    // 初始化物品位置（確保在地圖範圍內）
    item_x = X + 3'd3;
    item_y = Y + 3'd3;
  end
  
  // 七段顯示器顯示邏輯
  always @(posedge SYS_CLK or posedge RST) begin
    if (RST) begin
      seg <= 7'b1111111;
      an <= 4'b1110;
    end else begin
      // 將 point 的個位數顯示在七段顯示器
      // 注意：直接使用點數可能超過 9，需要進行 BCD 轉換或限制顯示
      if (point > 8'd9) begin
        digit <= 4'd0; // 超過 9 時重置為 0
      end else begin
        digit <= point[3:0];
      end
      seg <= seg_code[digit];
      an <= 4'b1110; // 只顯示個位數
    end
  end
  
  // 系統時鐘產生遊戲與 LED 時鐘
  always @(posedge SYS_CLK or posedge RST) begin
    if (RST) begin
      move_counter <= 25'd0;
      game_clk <= 1'b0;
      led_counter <= 25'd0;
      led_clk <= 1'b0;
    end else if (PAUSE) begin
      // 暫停時不更新計數器
    end else begin
      // 更新 move_counter
      if (move_counter < COUNT_TO - 1) begin
        move_counter <= move_counter + 1;
      end else begin
        game_clk <= ~game_clk;
        move_counter <= 25'd0;
      end
      
      // 更新 led_counter
      if (led_counter < LED_COUNT_TO - 1) begin
        led_counter <= led_counter + 1;
      end else begin
        led_clk <= ~led_clk;
        led_counter <= 25'd0;
      end
    end
  end
  
  // LED 顯示邏輯
  always @(posedge led_clk or posedge RST) begin
    if (RST) begin
      comm <= 3'b000;
      LedR <= 8'b11111111;
      LedG <= 8'b11111111;
      LedB <= 8'b11111111;
    end else begin
      // 更新 comm 信號
      if (comm == 3'b111)
        comm <= 3'b000;
      else
        comm <= comm + 1'b1;
      
      // 根據遊戲狀態顯示 LED 顏色
      if (state == END_GAME) begin
        LedG <= map[comm];
        LedB <= 8'b11111111; // 熄滅藍色 LED
      end else begin
        LedB <= map[comm];
        LedG <= 8'b11111111; // 熄滅綠色 LED
      end
      
      // 顯示物品位置的紅色 LED
      if (comm == item_x)
        LedR <= ~(1 << item_y); // 亮起特定 LED（主動低）
      else
        LedR <= 8'b11111111;    // 熄滅所有紅色 LED
    end
  end
  
  // 更新移動方向
  always @(posedge SYS_CLK or posedge RST) begin
    if (RST) begin
      move_dir <= 2'b00;
    end else begin
      if (UP && !DOWN && !LEFT && !RIGHT && move_dir != 2'b01)
        move_dir <= 2'b00;
      else if (DOWN && !UP && !LEFT && !RIGHT && move_dir != 2'b00)
        move_dir <= 2'b01;
      else if (LEFT && !UP && !DOWN && !RIGHT && move_dir != 2'b11)
        move_dir <= 2'b10;
      else if (RIGHT && !UP && !DOWN && !LEFT && move_dir != 2'b10)
        move_dir <= 2'b11;
    end
  end
  
  // 遊戲主邏輯
  always @(posedge game_clk or posedge RST) begin
    integer k; // 在 always 區塊開始處宣告
    
    if (RST) begin
      // 重置遊戲狀態
      X <= 3'b010;
      Y <= 3'b010;
      length <= 6'd3;
      state <= GAME;
      point <= 8'd0;
      
      // 重置地圖
      for (m = 0; m < 8; m = m + 1) begin
        map[m] <= 8'b11111111; // 熄滅所有 LED
      end
      
      // 重置蛇身位置
      for (n = 0; n < length; n = n + 1) begin
        body_mem_x[n] <= X;
        body_mem_y[n] <= Y;
      end
      
      // 重置物品位置
      item_x <= X + 3'd3;
      item_y <= Y + 3'd3;
    end else if (state == GAME) begin
      // 根據方向更新蛇頭位置
      case (move_dir)
        2'b00: Y <= Y + 1;
        2'b01: Y <= Y - 1;
        2'b10: X <= X - 1;
        2'b11: X <= X + 1;
      endcase
      
      // 更新地圖，亮起新位置
      map[X][Y] <= 1'b0; // 主動低，0 表示亮
      
      // 判斷是否取得物品
      if (X == item_x && Y == item_y) begin
        if (point >= 8'd254)
          state <= END_GAME;
        else
          point <= point + 1;
          
        // 更新物品位置，確保在範圍內
        if (move_dir == 2'b00 || move_dir == 2'b01) begin
          item_x <= (X + 3'd3 + 3'd2) % 3'd8;
          item_y <= (Y - 3'd3 + 3'd1) % 3'd8;
        end else begin
          item_x <= (X - 3'd3 - 1'd1) < 3'd0 ? 3'd0 : (X - 3'd3 - 1'd1);
          item_y <= (Y + 3'd3 - 3'd2) % 3'd8;
        end
      end
      
      // 更新蛇身
      // 熄滅尾巴位置
      map[body_mem_x[length - 1]][body_mem_y[length - 1]] <= 1'b1; // 主動低，1 表示熄滅
      
      // 移動蛇身
      for (k = 1; k < length; k = k + 1) begin
        body_mem_x[length - k] <= body_mem_x[length - k - 1];
        body_mem_y[length - k] <= body_mem_y[length - k - 1];
      end
      body_mem_x[0] <= X;
      body_mem_y[0] <= Y;
      
      // 碰撞檢測
      // 撞牆
      if (X == 3'd0 || X == 3'd7 || Y == 3'd0 || Y == 3'd7) begin
        state <= END_GAME;
      end
      
      // 撞到自己
      for (k = 1; k < length; k = k + 1) begin
        if (body_mem_x[k] == X && body_mem_y[k] == Y) begin
          state <= END_GAME;
        end
      end
    end
  end
  
endmodule