经典IC设计面试问题3
时间：10-02
整理：3721RD
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Tell me about verilogfile I/O?
OPEN A FILE
integer file;
file = $fopenr("filename");
file = $fopenw("filename");
file = $fopena("filename");
The function $fopenr opens an existing file for reading. $fopenw opens a new file for writing, and $fopena opens a new file for writing where any data will be appended to the end of the file. The file name can be either a quoted string or a reg holding the file name. If the file was successfully opened, it returns an integer containing the file number (1..MAX_FILES) or NULL (0) if there was an error. Note that these functions are not the same as the built-in system function $fopen which opens a file for writing by $fdisplay. The files are opened in C with 'rb', 'wb', and 'ab' which allows reading and writing binary data on the PC. The 'b' is ignored on Unix.
CLOSE A FILE
integer file, r;
r = $fcloser(file);
r = $fclosew(file);
The function $fcloser closes a file for input. $fclosew closes a file for output. It returns EOF if there was an error, otherwise 0. Note that these are not the same as $fclose which closes files for writing.
OPEN A FILE
integer file;
file = $fopenr("filename");
file = $fopenw("filename");
file = $fopena("filename");
The function $fopenr opens an existing file for reading. $fopenw opens a new file for writing, and $fopena opens a new file for writing where any data will be appended to the end of the file. The file name can be either a quoted string or a reg holding the file name. If the file was successfully opened, it returns an integer containing the file number (1..MAX_FILES) or NULL (0) if there was an error. Note that these functions are not the same as the built-in system function $fopen which opens a file for writing by $fdisplay. The files are opened in C with 'rb', 'wb', and 'ab' which allows reading and writing binary data on the PC. The 'b' is ignored on Unix.
CLOSE A FILE
integer file, r;
r = $fcloser(file);
r = $fclosew(file);
The function $fcloser closes a file for input. $fclosew closes a file for output. It returns EOF if there was an error, otherwise 0. Note that these are not the same as $fclose which closes files for writing.
That's right 多谢小编分享！
kanyixia
学习了
有这样的函数么$fopenr，我怎么不知道啊