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Request Download
Upload Download Functional Unit
The diagnostic services in this category provide services to upload and download content from or to the server/ECU
The following are the diagnostic services supported by Upload Download functional unit
Request Download
This service is used to initiate a data transfer from the client to the server which is also called Download. Once the server receives the request, the server should start its necessary steps to receive data before sending a positive response to the client. The service ID for Request Download is 0x34.
Request message definition
Data Format ID is to be seen each as a nibble of data. The high nibble specifies the compression method and the lower nibble specifies the encryption method
Address & length Format ID is one byte long and the higher nibble specifies memory size length and the lower nibble specifies the memory address length
The memory address is the starting address of the server memory to which the data needs to be written. It will always refer to the least significant address
Memory size is the total amount of data that needs to be transferred using the service.
