s32k312 CAN FIFO question?

[StephenYeh]

There are three Rx FIFO to be clarified. 

1. Enhanced Rx FIFO needs to set ID filter elements as the can message matching condition. Can the RX ID filter elements be dynamically modified?(RX can message reception not be stopped)

2. When modifying the RX ID filter elements, will the current CAN controller stop receiving all RX can messages? Or will only the modified RX ID filter elements be affected?

3. If any RX ID filter element modification need to turn off RX reception and re-config ID filter elements ,then re-start can message reception. Does NXP have execution time data for reference regarding the time it takes to turn off reception to apply new rules and restart RX reception?

[StephenYeh]

Hi Sir,

Would you help us to check with below question?

1. Our customer mentioned their previous project can support RX CAN message filter dynamically with AutoSar, what process that AutoSar implement RX can message filter dynamically?     And how NXP flexcan driver support RX can message filter changed with AutoSar?

2. Could we know how other customer handle the RX filter element modification dynamically in Enhanced Rx FIFO on S32K312?

3. Could you share the necessarily sample code for RX filter element reconfiguration? (We need do RX filter element reconfiguration as less steps).

[PetrS]

Hi,

1) do not know autosar so cannot comment its implementation. Certainly you can change filters but this must be done in Freeze mode, so a term dynamically is questionable as during Freeze other TX/RX process is not running.

2) nothing to add here

3) the procedure in mentioned in the RM chapter 74.3.8 Enhanced RX FIFO.

BR, Petr

[PetrS]

Hi,

1-2) ERFFEL registers can be written only in Freeze mode; otherwise, the module blocks them. Thus all RX/TX operations are stopped, as module must be in Freeze mode. 

3) as this is about entering/leaving Freeze mode the max time is specified in MCR[FRZACK] description.

BR, Petr