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DM36x open drain pins?

Michael Shklyarman
Genius 12245 points

Hi,

The I2C and GPIO modules' user guides for the DM36x devices mention open-drain pins, however no specific device datasheet have any mention of such. Could you please clarify if DM36x devices have open-drain pinsor it is just a documentation error?

thanks

Michael 

  • 0
    TI__Guru*** 138349 points
    Hi,

    I we are looking into this question and will get back to you soon

    thanks
    cesar
  • 0 in reply to Cesar
    TI__Mastermind 37500 points

    Hello,

    Following the sprufh3a.pdf, for I2C for DM36x, section 2.4 discusses that the use should be two bidirectional pins, with open drain capability.

    I do not see direct register support for open drain.   

    In the DM365 arm subsystem, sprufg5a.pdf, the PUPDCTL# - control the pullup pulldown, on/off controls.

    In the GPIO discussion, sprufh8c.pdf, Figure 1 it shows a general GPIO, that if its an input, you can combine it with pull up or pull down.   There are no discussions of OPEN DRAIN.

    sprufj0b.pdf - this also discusses open drain, but there is no direct software support method for GIO register in open drain.

    Although its not stated in the data manual, as GIO registers are for pinmuxing, software pullup / pulldown, and software IO, if a peripherial requires open drain,

    this would have to be based on pin muixing a set of bidirectional cells to one IO pin.

    I also don't see where you can control open drain from software registers.

    Regards,

    Joe QUIntal