Auto-Diag-14: Read Memory by Address — All Auto Tech

READ MEMORY BY ADDRESS

The read memory by address allows the client to read data from certain memory regions in the server.

The service ID for this service is 0x23

Important points about the Read Memory by Address

1. The client requests data from the server by providing the starting memory address and the size of memory to be read
2. The starting memory address and size is added in the data parameter section of the request message
3. The “address and length format Identifier” field will contain the size of the memory address and memory size data parameter length
4. To access certain memory regions, it can be designed that security access has to be granted by the ECU

Message flow examples

Let’s understand a scenario where the client tries to read 5 bytes of data from the server.

Assumptions:

1. Memory address — 0x4813
2. Memory size — 0x05
3. Memory addressing — 16 bit addressing

Request message

Positive Response message

Negative Response message

Supported negative response codes

Originally published at https://allautotech.net on May 23, 2021.