NAME

       srec_vmem - vmem file format

DESCRIPTION

       This  format  is  the Verilog VMEM format.  This is a hex format suitable for loading into
       Verilog simulations using the $readmemh call.

       The text file to be read shall contain only the following:
       White space (spaces, new lines, tabs, and form‐feeds)
       Comments (both types of C++ comment are allowed)
       Hexadecimal numbers

       White space and/or comments shall be used to separate the numbers.

       In the following discussion, the term "address" refers to an index  into  the  array  that
       models the memory.

       As  the  file is read, each number encountered is assigned to a successive word element of
       the memory.  Addressing is controlled both by specifying start and/or finish addresses  in
       the system task invocation and by specifying addresses in the data file.

       When  addresses appear in the data file, the format is an "at" character (@) followed by a
       hexadecimal number as follows:
              @hh...h

       Both uppercase and lowercase digits are allowed in the number.  No white space is  allowed
       between  the  @  and the number.  As many address specifications as needed within the data
       file can be used.  When the system task encounters  an  address  specification,  it  loads
       subsequent data starting at that memory address.

   Commentary
       There is no checksum in this format, which can generate false positives when guessing file
       formats on input.

       There is no indication of the word size in the file, since it is  dependent  on  the  word
       type  of the Verilog memory it is being read into.  SRecord will guess the word size based
       on the number of digits it sees in the numbers, but this is only a guess.

       SRecord will also assume that the numbers are to  be  loaded  big‐endian;  that  is,  most
       significant byte (first byte seen) into the lowest address covered by the word.

       You  can use the -byte‐swap filter to change the byte order; it takes an optional width of
       bytes to swap within.

   Size Multiplier
       In general, binary data will expand in sized by  approximately  2.9  times  (32‐bit),  3.1
       times (16‐bit) or 3.6 times (8‐bit) when represented with this format.

EXAMPLE

       Here is an example Verilog VMEM file.  It contains the data “Hello, World[rq] to be loaded
       at address 0x1000.
              @00000400 48656C6C 6F2C2057 6F726C64 0AFFFFFF

REFERENCE

       IEEE P1364‐2005/D2, Standard for Verilog Hardware Description  Language  (Draft),  section
       17.2.8 "Loading memory data from a file", p. 295.
       Copyright © 2003 IEEE
       http://www.boyd.com/1364/
       http://www.boyd.com/1364/1364‐2005‐d2.pdf.gz

COPYRIGHT

       srec_cat version 1.58
       Copyright  (C)  1998,  1999,  2000,  2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
       2010, 2011 Peter Miller

       The srec_cat program comes with ABSOLUTELY NO WARRANTY;  for  details  use  the  'srec_cat
       -VERSion  License'  command.  This is free software and you are welcome to redistribute it
       under certain conditions; for details use the 'srec_cat -VERSion License' command.

AUTHOR

       Peter Miller   E‐Mail:   pmiller@opensource.org.au
       /\/\*             WWW:   http://miller.emu.id.au/pmiller/