CODEWITHSUNDEEP
autosarnon-volatile
Teja
Teja

Reputation: 31

DEM Dependency on NVM

I am trying to understand the dependency of DTC's with DEM_NVRamNBlocks.

Does the number of DTC's effect the no of DEM_NVBlocks (DEM_NVBLOCK_PRIMARY)?

Upvotes: 2

Views: 2275

Answers (2)

TusharPaithankar
TusharPaithankar

Reputation: 45

DEM_NVRamNBlocks are used to store the DTC and it's information such as status byte, freeze frame data and extended data related to the DTC (This is to retain the information after shutdown).

Now depending upon the number of Blocks configured that many DTC's information can be stored into NVM (Also there is DTC displacement possible inside the NVM depending upon some paramters).

Upvotes: 1

marcin214
marcin214

Reputation: 71

Dem specification describes interaction with Nvm here

Dem module uses Nvm blocks for storage DTCs information (status byte, snapshot and extended data). If bit3 “confirmedDTC” from status byte is set to 1, than DTC is stored immediately or during Nvm_WriteAll.

Usually is configured less DemNvRamBlockId than DemEventParameter (mostly one DemEventParameter mapped to one DTC). If more DTCs than number of Nvm blocks have “confirmedDTC” set to 1, about what is stored first, decides DTC priority.

Type of configured memory block in DEM (primary, secondary or different) decides which event will be stored in this specific block.

Upvotes: 0

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