S-Records
-S-Record Format-
Chaplin@keinstr.uucp (Roger Chaplin) reposted an article written
by mcdchg!motmpl!ron (Ron Widell) that explained how Motorola
S-Records are formatted. This comes from a unix man page. No
mention of which version of Unix is specified. This section
of the FAQ is a bit long. An anonymous ftp archive is currently
being sought. When one is found, the section will be placed in
the archive.
SREC(4) UNIX 5.0 (03/21/84) SREC(4)
An S-record file consists of a sequence of specially formatted
ASCII character strings. An S-record will be less than or equal to
78 bytes in length.
The order of S-records within a file is of no significance and no
particular order may be assumed.
The general format of an S-record follow:
+------------------//-------------------//-----------------------+
| type | count | address | data | checksum |
+------------------//-------------------//-----------------------+
type A char-2- field. These characters describe the
type of record (S0, S1, S2, S3, S5, S7, S8, or
S9).
count A char-2- field. These characters when paired and
interpreted as a hexadecimal value, display the
count of remaining character pairs in the record.
address A char-4,6, or 8- field. These characters grouped
and interpreted as a hexadecimal value, display
the address at which the data field is to be
loaded into memory. The length of the field
depends on the number of bytes necessary to hold
the address. A 2-byte address uses 4 characters,
a 3-byte address uses 6 characters, and a 4-byte
address uses 8 characters.
data A char -0-64- field. These characters when paired
and interpreted as hexadecimal values represent
the memory loadable data or descriptive
information.
checksum A char-2- field. These characters when paired and
interpreted as a hexadecimal value display the
least significant byte of the ones complement of
the sum of the byte values represented by the
pairs of characters making up the count, the
address, and the data fields.
Each record is terminated with a line feed. If any
additional or different record terminator(s) or delay
characters are needed during transmission to the target
system it is the responsibility of the transmitting program
to provide them.
S0 Record The type of record is 'S0' (0x5330). The address
field is unused and will be filled with zeros
(0x0000). The header information within the data
field is divided into the following subfields.
mname is char-20- and is the
module name.
ver is char-2- and is the
version number.
rev is char-2- and is the
revision number.
description is char-0-36- and is a
text comment.
Each of the subfields is composed of ASCII bytes
whose associated characters, when paired,
represent one byte hexadecimal values in the case
of the version and revision numbers, or represent
the hexadecimal values of the ASCII characters
comprising the module name and description.
S1 Record The type of record field is 'S1' (0x5331). The
address field is interpreted as a 2-byte address.
The data field is composed of memory loadable
data.
S2 Record The type of record field is 'S2' (0x5332). The
address field is interpreted as a 3-byte address.
The data field is composed of memory loadable
data.
S3 Record The type of record field is 'S3' (0x5333). The
address field is interpreted as a 4-byte address.
The data field is composed of memory loadable
data.
S5 Record The type of record field is 'S5' (0x5335). The
address field is interpreted as a 2-byte value
and contains the count of S1, S2, and S3 records
previously transmitted. There is no data field.
S7 Record The type of record field is 'S7' (0x5337). The
address field contains the starting execution
address and is interpreted as 4-byte address.
There is no data field.
S8 Record The type of record field is 'S8' (0x5338). The
address field contains the starting execution
address and is interpreted as 3-byte address.
There is no data field.
S9 Record The type of record field is 'S9' (0x5339). The
address field contains the starting execution
address and is interpreted as 2-byte address.
There is no data field.
EXAMPLE
Shown below is a typical S-record format file.
S00600004844521B
S1130000285F245F2212226A000424290008237C2A
S11300100002000800082629001853812341001813
S113002041E900084E42234300182342000824A952
S107003000144ED492
S5030004F8
S9030000FC
The file consists of one S0 record, four S1 records, one S5
record and an S9 record.
The S0 record is comprised as follows:
S0 S-record type S0, indicating it is a header
record.
06 Hexadecimal 06 (decimal 6), indicating that six
character pairs (or ASCII bytes) follow.
00 00 Four character 2-byte address field, zeroes in
this example.
48 ASCII H, D, and R - "HDR".
1B The checksum.
The first S1 record is comprised as follows:
S1 S-record type S1, indicating it is a data record
to be loaded at a 2-byte address.
13 Hexadecimal 13 (decimal 19), indicating that
nineteen character pairs, representing a 2 byte
address, 16 bytes of binary data, and a 1 byte
checksum, follow.
00 00 Four character 2-byte address field; hexadecimal
address 0x0000, where the data which follows is to
be loaded.
28 5F 24 5F 22 12 22 6A 00 04 24 29 00 08 23 7C Sixteen
character pairs representing the actual binary
data.
2A The checksum.
The second and third S1 records each contain 0x13 (19)
character pairs and are ended with checksums of 13 and 52,
respectively. The fourth S1 record contains 07 character
pairs and has a checksum of 92.
The S5 record is comp