• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 97 subscribers
  • Views 245 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.

About duty cycle of uPP on C674x

RY9983
Guru 10570 points
Other Parts Discussed in Thread: TMS320C6748

Hello.
I would like to use uPP as clock master to connect ADC.
Does anyone let me know, please?

- What is duty cycle of uPP ?
  (I expect it is between 45% and 55%)

- Can I use upp as clock master?

Best regards,
RY

  • 0
    TI__Intellectual 1510 points

    Hi RY,

    Yes, duty cycle of uPP is between 45% to 55%. For your information, you can refer to the given link.

     

    Page 234

    http://focus.ti.com/lit/ds/symlink/tms320c6748.pdf

     

    Also, uPP can be used as master clock as it works in receive,  transmit and duplex mode. For that, you can refer to the following section.

    Section 6.26, Page 232

    http://focus.ti.com/lit/ds/symlink/tms320c6748.pdf

     

    Best Regards,

    Ankit Agrawal

  • 0 in reply to chitprad
    Guru 10570 points

    Hello Ankit.

    Thank you so much for your advice.
    I can not find the duty cycle in datasheet Page 234.
    How can I consider about duty cycle?

    When 1.3V core voltage, the Table 6-117 of datasheet describes below.
      #13 tw(OUTCLKH) : Pulse width, CHn_CLK high .. SDR mode 5ns[MIN],  DDR mode 10ns[MIN]
      #14 tw(OUTCLKL) : Pulse width, CHn_CLK low  .. SDR mode 5ns[MIN],  DDR mode 10ns[MIN]

    Does it mean 50% of duty cycle?
    From your answer, it is 45%-55%.
    Which does it mean 5% of error need to be considered ?

    Best regards,
    RY

  • 0 in reply to RY9983
    TI__Intellectual 1510 points

    Hi RY,

     

    Yes, that means 50% but as per my knowledge 45%-55% is allowed when duty cycle is 50%.

     

     

    Best Regards,

    Ankit

  • 0 in reply to chitprad
    Guru 10570 points

    Hi Ankit

    Thank you for your quick reply.
    I would like to follow your advice.
    Thanks again!

    Best regards,
    RY