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TMS320F28377D: CDC example, baud, class and subclass

Lenio Cacula
Genius 16710 points
Part Number: TMS320F28377D
Other Parts Discussed in Thread: C2000WARE,

Regarding the USB serial in C2000ware:

1. How to maximize the baud to take full advantage of the USB? More specifically, how should the code determine the value of DEFAULT_BIT_RATE and call out the following function:

UARTConfigSetExpClk(USB_UART_BASE, SysCtlLowSpeedClockGet(SYSTEM_CLOCK_SPEED),
DEFAULT_BIT_RATE, DEFAULT_UART_CONFIG);

2. For an Android tablet connected to the TMS320F28377D, how exactly will the device be enumerated? Will a generic Android driver recognize class and subclass of the device? 

Thank you!

  • 0
    TI__Mastermind 32995 points
    Hi Lenio,

    On the USB side of the communication, as a USB CDC class device, the baud rate is irrelevant. The serial communication is over USB and has a set transfer and bit rate. Changing the baud rate of the COM port will not make a difference.

    You can see a similar discussion here: www.microchip.com/.../m285533.aspx

    The bit rate in our example is for the UART or SCI. They are the same thing on the C28x. It isn't for the USB CDC communication.

    I am not sure if the windows drivers will work for the Android. We haven't test on an Android platform.

    But you can see on this forum post, another customer is using a Python program to communicate to the F2837x as a bulk device. The programming to send and receive to CDC or Bulk is fairly straight forward.

    e2e.ti.com/.../699680

    Regards,
    sal
  • 0 in reply to Sal Pezzino
    TI__Genius 16710 points
    Hi Sal,

    thanks for the reply, which answers the bit rate / throughput concern we have. I still wanted to get a bit deeper on the enumeration question and I am afraid I was not clear enough in my post. I did mention about Android, but that could apply to any OS or host in which the Delfino connects. (a) What are the differences in class ID's between the CDC and the bulk examples; (b) will special drivers need to be installed for either one of those; (c) will the Delfino be a universally recognized device?
  • 0 in reply to Lenio Cacula
    TI__Mastermind 32995 points
    Lenio,

    a) I am not sure what you mean when asking about the differences between class ID's...

    b) But, because they are different class devices, they need different drivers. We provide these in C2000Ware. The device and host pass different information in the enumeration process so they can connect and recognize the different types of devices.

    c) The Delfino will be recognized. Once the device driver is installed, it should be working properly (i.e. the enumeration process will suceed).

    Hope this helps,
    sal