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Original question:

TMS320F28335: F28335: eCAN - Receiving Remote Frames

TMS320F28335: F28335: eCAN - Overload Frames

Henrique T.
Intellectual 490 points
Part Number: TMS320F28335


Overload Frames are part of Can Specification (Bosch's CAN 2.0A/B Spec and ISO11898-1).

The eCAN Guide says that the 28335 eCAN module is fully compliant with CAN protocol, but haven't found any text about the usage of Overload Frames by the module.

The only part relating to Overload Condition is at page 74. But its not about Sending/Receiving Overloads Frames... its about handling overload situations by the CPU.

So, the module is compliant about Overload Frames?

It sends Overload Frames automatically? When? 

And what if the DSC receives an Overload Frame? What happens? 

  • 0
    TI__Mastermind 30255 points
    Hello

    Overload frames are supported, they are briefly mentioned in the "CAN Protocol Overview" section of the eCAN Reference Guide. The IP will handle when to send them and work as detailed in the spec.

    Best regards
    Chris
  • 0 in reply to Christopher Chiarella
    TI__Guru* 95315 points

    I dug up my CAN archives of online discussion groups and found the below from a few years back which explains the OF:

     

    "..The overload frame was designed to enable a node to prevent other nodes from transmitting until this device has finished processing the previous message i.e when the device's state machine was incapable of internally processing the message before another one would show up on the bus. It is an artifact of older devices with low clock speeds. You will seldom encounter it in the current generation of devices with high clock speeds. The protocol specification states that a node has to be able to process an overload frame if it shows up at the end of a message.  It doesn't state that a node has to be able to generate one. "