Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!ncar!noao!mcdsun!mcdchg!michael
From: michael@mcdchg.UUCP (Michael Bodine)
Newsgroups: comp.sys.m68k
Subject: Re: Motorola "S records"
Message-ID: <7439@mcdchg.UUCP>
Date: 29 Apr 88 15:53:56 GMT
References: <9200@agate.BERKELEY.EDU>
Reply-To: michael@mcdchg.UUCP (Michael Bodine)
Organization: Motorola Microcomputer, Schaumburg, IL
Lines: 54

swackham@violet.berkeley.edu.UUCP writes:
> Motorola "S records".  What is the format/structure of these records?
> Please E-mail responses to:  swackham@violet.berkeley.edu
Altho you requested mailed responses, i've noticed requests for Srecord
format a couple of times recently, so i'm posting this for general
interest:

Motorola S-records are intended to provide an ASCII-encoded hex format
for binary records allowing the downloading of executable code or data
into target systems or EPROM programs or communication of same across
media prone to problems with binary transmissions.  Most PROM blowers
and M68K family debug tools understand the S-record format, which is as
follows:
  Sxllaaaa[aa[aa]]dddd......ddcc
where:
Sx -- is the S-record format descriptor:
  S0 : header record, which is unused by almost any interpreter and
	which may contain standard ASCII data describing file contents
  S1 : a binary record with a 16-bit address
  S2 : a binary record with a 24-bit address
  S3 : a binary record with a 32-bit address
  S5 : a block record, contains the number of S1, S2 or S3 records in
	the following block, in the address field.  dd data field is
 	empty.  Normally not used.
  S7 : termination record for a block of S3 records.  Address field will
	optionally contain the start address for the completed program.
  S8 : termination record for S2 records.
  S9 : termination record for S1 records.
  Note that only one termination record is recquired at the end of the
  file to take the target out of load mode.  S1, S2 and S3 records may 
  be intermixed quite randomly, altho most vendors will typically choose
  the largest address in the file and make all S-records use that type of
  descriptor.
ll -- the number of character pairs in the record inluding the descriptor
  and length, but not including the checksum
aaaa[aa[aa]] -- the address into which the data is to be loaded, where the
  number of bits represented is 16 for S1, 24 for S2 and 32 for S3.
dd -- a ASCII-coded hexadecimal pair representing one byte of binary data
cc -- the low-order byte of the one's complement sum of all byte pairs in
  the record except the descriptor and the checksum, that is, the length,
  address and data fields are checksummed.

An example:
S1130000285F245F2212226A000424290008237C2A
SXllaaaaddddddddddddddddddddddddddddddddcc

A similar description of S-records is included with almost every firmware
debugger manual available from Motorola.

Enjoy!
-- 
[ Michael Bodine, michael@mcdchg.UUCP Opinions expressed are mine and haven't  ]
[ been seen, commented on or in any way approved or even allowed by Motorola   ]
[ MicroComputer Division, Motorola General Systems Group or Motorola, Inc.     ]
[ No one else agrees with me;  why should my employer?			       ]