Страница 1 мировой engineering стандарты общая спецификация

8.7.2 Request Message Definition (Table 91).
Table 91: ReadMemoryByAddress Request Message
Data Byte
Parameter Name
Cvt Hex Value Mnemonic
#1
ReadMemoryByAddress Request Service Id
M
23
SIDRQ
#2
#3
#4
#5
memoryAddress = [
memoryAddress (Byte1 - MSB),
memoryAddress (Byte2),
memoryAddress (Byte3),
memoryAddress (Byte4) ] 
Note 1
M
M
C1
C2
xx
MA_
B1
B2
B3
B4
#4/5/6
#5/6/7
memorySize = [
memorySize(High Byte),
memorySize(Low Byte)]
M
xx
MS_
B1
B2
C1: 
Byte 3 is present when the memoryAddress parameter contains 3 or 4 bytes.
C2: 
Byte 4 is present when the memoryAddress parameter contains 4 bytes.
Note 1: 
Byte1 in the memoryAddress parameter is always the most significant byte of the address and the last byte of the memoryAddress
parameter (Byte2 for 2-byte addressing, Byte3 for 3 byte addressing, or Byte4 for 4 byte addressing) is always the least significant byte of
the memoryAddress parameter.
8.7.2.1 Request Message Sub-Function $Level Parameter Definition. 
Because this service is defined as a
single operation, there are no sub-function levels required or valid for the request message.
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Page 119
GM WORLDWIDE ENGINEERING STANDARDS
GMW3110
8.7.2.2 Request Message Data Parameter Definitions (Table 92).
Table 92: Request Message Data Parameter Definition
Definition
memoryAddress
The parameter memoryAddress is used to select the starting address of ECU memory from which data is to be
retrieved. A portion of the memoryAddress parameter (most significant bits or bytes) can be used as a
memoryIdentifier.
An example of the use of a memoryIdentifier would be a dual processor ECU with 16-bit addressing and
memory address overlap (when a given address is valid for either processor but yields a different physical
memory device). In this case, a 3-byte memoryAddress parameter can be specified and the most significant
byte of the memoryAddress parameter could then be used to select which physical memory device the tester is
attempting to retrieve data from. Any usage of a memoryIdentifier shall be documented in the appropriate CTS,
SSTS or supplemental diagnostic specification referenced by the CTS or SSTS.