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AM3352: UART user guide

Takayuki Miyazaki
Genius 10120 points

Part Number: AM3352

Hello team,

Our customer is looking for AM335x UART user Guide, however, they were not able to find detail document for UART. As far as I checked, it seems UART information(section 19) is just described in TRM. Should customer check this section and Linux-SDK source code/Processor-SDK-Guide ? If your will be able to share any helpful document/URL with us, it will be appreciated. (Customer is developing their system with Processor -Linux-SDK)

Anyway, I received some inquiries about UART function from customer.

1. UART Transmit

If the Stop-Bit is set to 1 bit after transmitting 10 bits, will the next data be transmitted continuously? Or is there any interval between sending the stop bit and the next start bit? 

2. UART Receiving

2-1. Regarding internal clock of Sampling Data, how many times this clock is baud-rate?

2-2. When is the Stop-bits checked under receiving data?

2-3. Is there any limitation of interval/timing between stop-bits and start-bit ?

 

Best regards,

Miyazaki

  • 0
    TI__Guru**** 174881 points

    Hi Miyazaki-san,

    Yes, the TRM has all the details about the UART hardware. If the customer want to know more about the UART usage in Linux kernel, the Processor SDK Developer's Guide you referred is the place to check.

    Takayuki Miyazaki said:
    If the Stop-Bit is set to 1 bit after transmitting 10 bits, will the next data be transmitted continuously? Or is there any interval between sending the stop bit and the next start bit? 

    Assume all data are in the TX FIFO, the next data will be transmitted immediately without any bus idle time between the stop bit and next start bit.

    Takayuki Miyazaki said:
    2-1. Regarding internal clock of Sampling Data, how many times this clock is baud-rate?

    I don't understand the question. The AM335x UART functional clk is always 48MHz regardless the baud rate.

    Takayuki Miyazaki said:
    2-2. When is the Stop-bits checked under receiving data?

    I don't understand the question. The stop bit is always at the end of each byte transfer and the UART hardware check for it, and the checking is transparent to user space applications.

    Takayuki Miyazaki said:
    2-3. Is there any limitation of interval/timing between stop-bits and start-bit ?

    No.

  • 0 in reply to Bin Liu
    TI__Genius 10120 points

    Hi Bin,

    Thanks for your comments. I translated customer’s inquiries into English simply. I’m sorry for bothering you. However, I believe your comments are helpful of customer. I shared your comments with our customer.

    Best regards,

    Miyazaki

  • 0 in reply to Takayuki Miyazaki
    TI__Guru**** 174881 points

    It was not bothering at all :) Please let me know if the customer has further questions.