• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 54 subscribers
  • Views 751 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.

UART Framing Error on CC2538

Nomo
Guru 16800 points
Other Parts Discussed in Thread: CC2538

Hello,

On my customer's board, CC2538 is connected to CPLD, which is using UART.
And, CC2538 is in PM2 sometimes.
My customer tries to send UART data from CPLD to CC2538 after waking up from PM2.
However, Break Error and Framing Error occur.
I have the following questions.

1. In my customer's system, the UART data transmission starts after 300us of the waking up signal.
   Therefore the wait time is double of the wakeup time written in datasheet (136us typical).
   If 300us waiting time is not enough, do Break Error and Framing Error occur?

2. After waking up from PM2, are UART_RSR and UART_ECR set?

3. Is there the procedure to use UART after the waking up from PM2? For example, before using UART, the status register must be cleared.

Best Regards,

Nomoto

  • 0
    TI__Genius 9180 points
    I have some questions to further my understanding of this issue:

    Which SW package and version or you using on CC2538?
    Is the framing and break error seen on the Host MCU or the CC2538?
    Is this seen on the first transmission or all subsequent transmissions after a sleep?
    Is the Host MCU also put in a low power mode?

    Regards,
    TC.
  • 0 in reply to TopCat
    Guru 16800 points

    Hello TopCat-asn,

     

    Thank you for your reply.

    TopCat said:
    Which SW package and version or you using on CC2538?

    SW package is my customer's original one.

     

    TopCat said:
    Is the framing and break error seen on the Host MCU or the CC2538?

    On CC2538. CC2538 is used as receiver.

     

    TopCat said:
    Is this seen on the first transmission or all subsequent transmissions after a sleep?

    It is seen on the first transmission after a sleep.

     

    TopCat said:
    Is the Host MCU also put in a low power mode?

    No, the host mcu (CPLD) is in active.

     

    Best Regards,

     

    Nomoto

  • 0 in reply to TopCat
    Guru 16800 points

    Hello,

    Have you any updates on my thread?

    Best Regards.

    Nomoto

  • 0 in reply to Nomo
    TI__Genius 9180 points
    Hello Nomoto-san,
    Sorry for the delay.

    I am still am unsure which SW is being run on the CC2538, without knowing this I do not know what UART drivers and sleep mechanisms are being used. Is the UART line being configured to wake the CC2538 when it enters sleep? If so there maybe need for a dummy byte transmitted over UART to wake the CC2538 correctly before transmitting real data.

    Regards,
    TC.
  • 0 in reply to TopCat
    Guru 16800 points

    Hello TC-san,

    Thank you for your reply.
    I apologize to tell you wrong information, and the framing error doesn't occur in first transmission after a sleep.

    As a analysis conclusion, the framing error occurs at the timing of the transition from 16 MHz RC oscillator operation to 32 MHz operation.
    Therefore, my customer tries not to transmit the data during the transition of clock source.

    Best Regards,

    Nomoto

     

     

  • 0 in reply to Nomo
    TI__Genius 9180 points
    Nomoto-san,
    Thank you for the update.

    Regards,
    TC.