• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 98 subscribers
  • Views 736 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.

Smart Reflex: VID Vout High, Low, Init values for CVDD

Courtney Cooley
Prodigy 235 points

Other Parts Discussed in Thread: UCD7242

Hello,

I have a design which utilizes the UCD9222 Smart Reflex Controller to control the power driver for the CVDD rail of the TCI6604 DSP (1.25GHz). My UCD9222 configuration file is modeled after the UCD9222 configuration file for the TMDXEVM6678L evaluation board (file: TMDXEVM6678L_UCD9222_16May11_ver5.xml). The values I have been programming to the UCD9222 for the CVDD VID config are the exact same values used for the evaluation board:

VID Vout Low: 0.700

VID Vout High: 1.103V

VID Code Init: 0.949V (VID CODE 39)

I am wondering now if these are the best values to use. Can you please tell me what the Vout Low, High and Init values should be set to for the CVDD rail of the 1.25GHz, 2.0 silicon, TCI6604 DSP?

Thank you very much.

-Courtney

  • 0
    TI__Mastermind 42545 points

    Hi Courtney,

    The values you've listed are correct for the TCI6604 and for all of the Keystone devices.   The VCNTL interface will present the proper VID code needed for the specific silicon device and the associated voltage level for the VID values are listed in Table 12 of the Hardware Design Guide. 

    You mentioned that you based your design on the C6678 EVM and that you're using the TCI6604 at 1.25GHz.  The EVM is designed for the current needs of the C6678 running at 1GHz.  Did you calculate the current requirements for your design using the power spreadsheet available on TI.com?  The TCI6604 running at 1.25GHz may exceed the current limits of the UCD7242 as it's connected on the EVM.

  • 0 in reply to Bill Taboada
    Prodigy 235 points

    Thanks Bill,

    I looked through the Hardware Design Guide before submitting my post, but I didn't make the connection between the table and the VID settings in the Fusion GUI. To answer your question, I did calculate the current requirements with the power estimate spreadsheet. I tied the outputs of the UCD7242 together in my design in order to be able to supply enough current.

    -Courtney