verilog ifdef_verilog define

注意：feof判断文件结束是通过读取函数fread/fscanf等返回错误来识别的，故而判断文件是否结束应该是在读取函数之后进行判断。比如，在while循环读取一个文件时，如果是在读取函数之前进行判断，则如果文件最后一行是空白行，可能会造成内存错误。

https://blog.csdn.net/Chauncey_wu/article/details/90289749

1.打开文件

　　integer file_id;

　　file_id = fopen(“file_path/file_name”);

2.写入文件：$fmonitor,$fwrite,$fdisplay,$fstrobe

　　//$fmonitor只要有变化就一直记录

　　$fmonitor(file_id, “%format_char”, parameter);

　　$fmonitor(file_id, “%m: %t in1=%d o1=%h”, $time, in1, o1);

//$fwrite需要触发条件才记录

　　$fwrite(file_id, “%format_char”, parameter);

//$fdisplay需要触发条件才记录

　　$fdisplay(file_id, “%format_char”, parameter);

$fstrobe();

3.读取文件：$fread

　　integer file_id;

　　file_id = $fread(“file_path/file_name”, “r”);

4.关闭文件：$fclose

　　$fclose(fjile_id);

5.由文件设定存储器初值：$readmemh，$readmemb

　　$readmemh(“file_name”, memory_name”); //初始化数据为十六进制

　　$readmemb(“file_name”, memory_name”); //初始化数据为二进制

6、文件显示：$monitor,$write，$display

　$display,$write用于输出信息

　　$display(“rvel = %h hex %d decimal”,rvel,rvel);

　　$monitor($time, ,”rxd = %b txd = %b”,rxd ,txd)

6、文件定位

　　$fseek，文件定位，可以从任意点对文件进行操作；

　　$fscanf，对文件一行进行读写。

7、退出仿真器$finish

8、随机数据产生：$random

1. 下面是一些常见的应用：

2. 1、读写文件

3. `timescale 1 ns/1 ns

4. module FileIO_tb;

5. integer fp_r, fp_w, cnt;

6. reg [7:0] reg1, reg2, reg3;

7. initial begin

8. fp_r = $fopen("data_in.txt", "r");

9. fp_w = $fopen("data_out.txt", "w");

10.  

11. while(!$feof(fp_r)) begin

12. cnt = $fscanf(fp_r, "%d %d %d", reg1, reg2, reg3);

13. $display("%d %d %d", reg1, reg2, reg3);

14. $fwrite(fp_w, "%d %d %d\n", reg3, reg2, reg1);

15. end

16.  

17. $fclose(fp_r);

18. $fclose(fp_w);

19. end

20. endmodule

21. 2、

22. integer file, char;

23. reg eof;

24. initial begin

25. file = $fopenr("myfile.txt");

26. eof = 0;

27. while (eof == 0) begin

28. char = $fgetc(file);

29. eof = $feof (file);

30. $display ("%s", char);

31. end

32. end

33. 3、文件处理定位

34. `define SEEK_SET 0

35. `define SEEK_CUR 1

36. `define SEEK_END 2

37. integer file, offset, position, r;

38. r = $fseek(file, 0, `SEEK_SET);

39. r = $fseek(file, 0, `SEEK_CUR);

40. r = $fseek(file, 0, `SEEK_END);

41. r = $fseek(file, position, `SEEK_SET);

42. 　　4、

43. integer r, file, start, count;

44. reg [15:0] mem[0:10], r16;

45. r = $fread(file, mem[0], start, count);

46. r = $fread(file, r16);

47. 　　5、

48. integer file, position;

49. position = $ftell(file);

50. 6、

51. integer file, r, a, b;

52. reg [80*8:1] string;

53. file = $fopenw("output.log");

54. r = $sformat(string, "Formatted %d %x", a, b);

55. r = $sprintf(string, "Formatted %d %x", a, b);

56. r = $fprintf(file, "Formatted %d %x", a, b);

57. 7、

58. integer file, r;

59. file = $fopenw("output.log");

60. r = $fflush(file);

61. 8、

62. // This is a pattern file - read_pattern.pat

63. // time bin dec hex

64. 10: 001 1 1

65. 20.0: 010 20 020

66. 50.02: 111 5 FFF

67. 62.345: 100 4 DEADBEEF

68. 75.789: XXX 2 ZzZzZzZz

69. `timescale 1ns / 10 ps

70. `define EOF 32'hFFFF_FFFF

71. `define NULL 0

72. `define MAX_LINE_LENGTH 1000

73.  

74. module read_pattern;

75. integer file, c, r;

76. reg [3:0] bin;

77. reg [31:0] dec, hex;

78. real real_time;

79. reg [8*`MAX_LINE_LENGTH:0] line;

80.  

81. initial

82. begin : file_block

83. $timeformat(-9, 3, "ns", 6);

84. $display("time bin decimal hex");

85. file = $fopenr("read_pattern.pat");

86. if (file == `NULL) // If error opening file

87. disable file_block; // Just quit

88.  

89. c = $fgetc(file);

90. while (c != `EOF)

91. begin

92.  

93. if (c == "/")

94. r = $fgets(line, `MAX_LINE_LENGTH, file);

95. else

96. begin

97. // Push the character back to the file then read the next time

98. r = $ungetc(c, file);

99. r = $fscanf(file," %f:\n", real_time);

100.  

101. // Wait until the absolute time in the file, then read stimulus

102. if ($realtime > real_time)

103. $display("Error - absolute time in file is out of order - %t",

104. real_time);

105. else

106. #(real_time - $realtime)

107. r = $fscanf(file," %b %d %h\n",bin,dec,hex);

108. end // if c else

109. c = $fgetc(file);

110. end // while not EOF

111.  

112. r = $fcloser(file);

113. end // initial

114.  

115. // Display changes to the signals

116. always @(bin or dec or hex)

117. $display("%t %b %d %h", $realtime, bin, dec, hex);

118.  

119. endmodule // read_pattern

120. 9、自动比较输出结果

121. `define EOF 32'hFFFF_FFFF

122. `define NULL 0

123. `define MAX_LINE_LENGTH 1000

124. module compare;

125. integer file, r;

126. reg a, b, expect, clock;

127. wire out;

128. reg [`MAX_LINE_LENGTH*8:1];

129. parameter cycle = 20;

130.  

131. initial

132. begin : file_block

133. $display("Time Stim Expect Output");

134. clock = 0;

135.  

136. file = $fopenr("compare.pat");

137. if (file == `NULL)

138. disable file_block;

139.  

140. r = $fgets(line, MAX_LINE_LENGTH, file); // Skip comments

141. r = $fgets(line, MAX_LINE_LENGTH, file);

142.  

143. while (!$feof(file))

144. begin

145. // Wait until rising clock, read stimulus

146. @(posedge clock)

147. r = $fscanf(file, " %b %b %b\n", a, b, expect);

148.  

149. // Wait just before the end of cycle to do compare

150. #(cycle - 1)

151. $display("%d %b %b %b %b", $stime, a, b, expect, out);

152. $strobe_compare(expect, out);

153. end // while not EOF

154.  

155. r = $fcloser(file);

156. $stop;

157. end // initial

158.  

159. always #(cycle / 2) clock = !clock; // Clock generator

160.  

161. and #4 (out, a, b); // Circuit under test

162. endmodule // compare

163. 10、从文件中读数据到mem（这个好像一般人用的最多了）

164. `define EOF 32'HFFFF_FFFF

165. `define MEM_SIZE 200_000

166. module load_mem;

167. integer file, i;

168. reg [7:0] mem[0:`MEM_SIZE];

169. reg [80*8:1] file_name;

170. initial

171. begin

172. file_name = "data.bin";

173. file = $fopenr(file_name);

174. i = $fread(file, mem[0]);

175. $display("Loaded %0d entries \n", i);

176. i = $fcloser(file);

177. $stop;

178. end endmodule // load_mem