All UDS services

Request Download

0x34

The Request Download service initiates a data download sequence by requesting the server to prepare for receiving data at the specified memory location.

✕Negative response codes
0x130x220x310x330x70

Request

SID 0x34 · 5 bytes
Len (bits)
Parameter description
Value (hex)
8
Request Download SID
0x34
4
compressionMethodSpecifies the compression algorithm applied to the data being transferred.
4
encryptingMethodSpecifies the encryption algorithm applied to the data being transferred.
4
memorySizeLengthSpecifies the byte length of the memory size field.
0x0-0xF
4
memoryAddressLengthSpecifies the byte length of the memory address field.
0x0-0xF
n*
8
memoryAddressTarget memory address where the downloaded data will be stored.
0x00-0xFF
m*
8
memorySizeTotal number of bytes to be downloaded.
0x00-0xFF

n = value of memoryAddressLength

m = value of memorySizeLength

Positive response

SID 0x74
Len (bits)
Parameter description
Value (hex)
8
Request Download SID
0x74
4
reserved
0x0-0xF
4
maxNumberOfBlockLengthBytesNumberNumber of bytes used to encode the maxNumberOfBlockLength value.
0x0-0xF
m*
8
maxNumberOfBlockLengthMaximum number of data bytes the server can receive per TransferData request.
0x00-0xFF

m = value of maxNumberOfBlockLengthBytesNumber

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