• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 376 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TCAN1048AV-Q1: question about TXD Dominant Timeout (DTO) and Minimum Data Rate

Jay wang
Expert 4271 points

Part Number: TCAN1048AV-Q1

Tool/software:

hi expert

i saw the following words in datasheet. i have a question about the following formula.

when we calculate the min data rate, why do this formula use 1.2ms, rather than use 4ms?

  • 0
    TI__Guru 63857 points

    Hi Jay,

    Please note that the min data rate is based on the shortest possible time a dominant bit is held, as this is essential in ensuring all nodes can detect and respond to the dominant state. Using the max dominant timeout could lead to situations where nodes can incorrectly assume the bus is free. Hence, the min dominant timeout as the shortest time the dominant bit is held - is more effective, thanks.

    Best Regards,

    Michael.

  • 0 in reply to Michael Ikwuyum
    TI__Expert 4271 points

    hi Michael

    thanks for your quick reply.

    i can understand the following words.

    Michael Ikwuyum said:
    as this is essential in ensuring all nodes can detect and respond to the dominant state.

    can you further explain the following words. why can we use 4ms. why do nodes incorrectly assume the bus is free?

    Michael Ikwuyum said:
    Using the max dominant timeout could lead to situations where nodes can incorrectly assume the bus is free
  • +1 in reply to Jay wang
    TI__Guru 63857 points

    Hi Jay,

    The max dominant timeout represents the longest duration that the node can hold the bus in a dominant state. The protocol relies on a clear understanding of the bus state among all nodes. If the max is used, the nodes might not synchronize effectively and this can lead to miscommunication as to when the bus is free or busy.

    Hence, if max is used without releasing the bus, other nodes can incorrectly assume bus availability. For example, if nodes rely on max during arbitration, they might interpret the bus state after the timeout expires. If the node assumes the bus is free and attempts to transmit, collision is possible. Furthermore, if nodes rely on the max, the nodes can be unnecessarily delayed in their transmissions and this can lead to increased latency and lower overall throughput, thanks.

    Best Regards,

    Michael.