Denverton SATA Issue - How to set the SATA De-Emphasis value to -9 dB

Dear All:

     I use IntekPLEVT tool to test the Denverton platform. In PLEVT tool ,our SATA port-3 must set the De-Emphasis value  to -9 dB.

    And now i cannot find any information about how to set the SATA De-Emphasis in the EDS document. I want our platform can set the SATA De-Emphasis value  to -9 dB at initialization.

    Dose any one know how to set? Or should I read other documents?

    Thanks a lot!