A file in Motorola S-record format is an ASCII file. There are three different
formats:
S19 for 16-bit address
S2 for 24-bit address
S3 for 32-bit address
The files consist of optional symbol table information, data specifications
for loading memory, and a terminator record.
[ $$ {module_record}
symbol records
$$ [ module_record ]
symbol_records
$$]
header_record
data_records
record_count_record
terminator_record
Module Record (Optional)
Each object file contains one record for each module that is a component of it. This
record contains the name of the module. There is one module record for each relocatable
object created by the assembler. The name of the relocatable object module
contained in the record comes from the IDNT directive. For absolute objects created
by the linker, there is one module record for each relocatable object file linked,
plus an additional record whose name comes from the NAME command for the
linker.
Example:
$$ MODNAME
Symbol Record (Optional)
As many symbol records as needed can be contained in the object module. Up to 4
symbols per line can be used, but it is not mandatory that each line contain 4
symbols. A module can contain only symbol records.
Example:
APPLE $00000 LABEL1 $ODOC3
MEM $OFFFF ZEEK $01947
The module name associated with the symbols can be specified in the
module_record preceding the symbol records.
Example:
$$MAIN
Symbols are assumed to be in the module named in the preceding module_record
until another module is specified with another module_record. Symbols defined by
the linker's PUBLIC command appear following the first module record, which
indicates the name of the output object module specified by the linker's NAME
command.
Each object module has exactly one header record with the following format:
S00600004844521B
Description:
S0 Identifies the record as a header record
06 The number of bytes following this one
0000 The address field, which is ignored
484452 The string HDR in ASCII
1B The checksum
A data record specifies data bytes that are to be loaded into memory. Figure 1
shows the format for such a record. The columns shown in the figure represent half
of a byte (4 bits).
---------------------------------------------
| 1 2 3 4 5 6 7 8 9 ... 40 41 42 |
| |
| S ID byte load data...data checksum |
| count address 1 n |
---------------------------------------------
Figure 1: Data Record Formatter 16-Bit Load Address
Column Description
1 Contains the ASCII character S, which indicates the start of
a record in Motorola S-record format.
2 Contains the ASCII character identifying the record type.
For data records, this character is 1.
3 to 4 Contain the count of the number of bytes following this one
within the record. The count includes the checksum and the
load address bytes but not the byte count itself.
5 to 8 Contain the load address. The first data byte is to be loaded
into this address and subsequent bytes into the next sequential
address. Columns 5 and 6 contain the high-order address
byte, and columns 7 and 8 contain the low-order address byte.
9 to 40 Contain the specifications for up to 16 bytes of data.
41 to 42 Contain a checksum for the record. To calculate this, take the
sum of the values of all bytes from the byte count up to the
last data byte, inclusive, modulo 256. Subtract this result
from 255.
A data record specifies data bytes that are to be loaded into memory. Figure 2
shows the format for such a record. The columns shown in the figure represent half
of a byte (4 bits).
----------------------------------------------------
| 1 2 3 4 5 6 7 8 9 10 11 ... 42 43 44 |
| |
| S ID byte load data...data checksum |
| count address 1 n |
----------------------------------------------------
Figure 2: Data Record Format for 24-Bit Load Address
Column Description
1 Contains the ASCII character S, which indicates the start of
a record in Motorola S-record format.
2 Contains the ASCII character identifying the record type.
For data records, this character is 2.
3 to 4 Contain the count of the number of bytes following this one
within the record. The count includes the checksum and the
load address bytes but not the byte count itself.
5 to 10 Contain the load address. The first data byte is to be loaded
into this address and subsequent bytes into the next sequential
address. Columns 5 and 6 contain the high-order address
byte, and columns 9 and 10 contain the low-order address byte.
11 to 42 Contain the specifications for up to 16 bytes of data.
43 to 44 Contain a checksum for the record. To calculate this, take the
sum of the values of all bytes from the byte count up to the
last data byte, inclusive, modulo 256. Subtract this result
from 255.
A data record specifies data bytes that are to be loaded into memory. Figure 3
shows the format for such a record. The columns shown in the figure represent half
of a byte (4 bits).
----------------------------------------------------------
| 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 44 45 46 |
| |
| S ID byte load data...data checksum |
| count address 1 n |
----------------------------------------------------------
Figure 3: Data Record Format for 32-Bit Load Address
Column Description
1 Contains the ASCII character S, which indicates the start of
a record in Motorola S-record format.
2 Contains the ASCII character identifying the record type.
For data records, this digit is 3 for 32-bit addresses.
3 to 4 Contain the count of the number of bytes following this one
within the record. The count includes the checksum and the
load address bytes but not the byte count itself.
5 to 12 Contain the load address. The first data byte is to be loaded
into this address and subsequent bytes into the next sequential
address. Columns 5 and 6 contain the high-order address
byte, and columns 11 and 12 contain the low-order address byte.
13 to 44 Contain the specifications for up to 15 bytes of data.
45 to 46 Contain a checksum for the record. To calculate this, take the
sum of the values of all bytes from the byte count up to the
last data byte, inclusive, modulo 256. Subtract this result
from 255.作者: McuPlayer 時間: 2009-6-19 00:50
*****************************************************************************************
Record Count Record (S5)
The record count record verifies the number of data records preceding it. Figure 4
shows the format for such a record. The columns shown in the figure represent half
of a byte (4 bits).
--------------------------------------
| 1 2 3 4 5 6 7 8 9 10 |
| |
| S ID byte # of data checksum |
| count records |
--------------------------------------
Figure 4: Record Count Record Format
Column Description
1 Contains the ASCII character S, which indicates the start of
a record in Motorola S-record format.
2 Contains the ASCII character 5, which indicates a record
count record.
3 to 4 Contain the byte count, ASCII string 03.
5 to 8 Contain the number of data records in this file. The high-
order byte is in columns 5 and 6.
9 to 10 Contain the checksum for the record.
Example:
S503010DEE
The example above shows a record count record indicating a total of 269 records
(0x010D) and a checksum of 0xEE.
A terminator record specifies the end of the data records. Figure 5 shows the
format for such a record. The columns shown in the figure represent half of a byte
(4 bits).
-------------------------------------
| 1 2 3 4 5...12 13 14 |
| |
| S ID byte load checksum |
| count address |
-------------------------------------
Figure5: Terminator Record Format for 32-Bit Load Address
Column Description
1 Contains the ASCII character S, which indicates the start of
a record in Motorola S-record format.
2 Contains the ASCII character 7, which indicates a 32-bit
load address.
3 to 4 Contain the byte count, ASCII string 04.
5 to 12 Contain the load address that is either set to zero or to the
starting address specified in the END directive or START
command (there are no data bytes).
A terminator record specifies the end of the data records. Figure 6 shows the
format for such a record. The columns shown in the figure represent half of a byte
(4 bits).
----------------------------------------
| 1 2 3 4 5 6 7 8 9 10 11 12 |
| |
| S ID byte load checksum |
| count address |
----------------------------------------
Figure 6: Terminator Record Format for 24-Bit Load Address
Column Description
1 Contains the ASCII character S, which indicates the start of
a record in Motorola S-record format.
2 Contains the ASCII character 8, which indicates a 24-bit
load address.
3 to 4 Contain the byte count, ASCII string 04.
5 to 10 Contain the load address, which is either set to zero or to the
starting address specified in the END directive or START
command. There are no data bytes.
11 to 12 Contain the checksum for the record.
Example:
S804000AF0001
The previous example shows a terminator record with a 24-bit load address of
0x000AF0 and a checksum of 0x01.
A terminator record specifies the end of the data records. Figure 7 shows the
format for such a record. The columns shown in the figure represent half of a byte
(4 bits).
-------------------------------------
| 1 2 3 4 5 6 7 8 9 10 |
| |
| S ID byte load checksum |
| count address |
-------------------------------------
Figure 7: Terminator Record Format for 16-Bit Load Address
Column Description
1 Contains the ASCII character S, which indicates the start of
a record in Motorola S-record format.
2 Contains the ASCII character 9, which indicates a 16-bit
load address.
3 to 4 Contain the byte count, ASCII string 04.
5 to 8 Contain the load address, which is either set to zero or to the
starting address specified in the END directive or START
command (there are no data bytes).