Hi,
As I understand it, you have some inquiries related using SIV device for SATA. To ensure we on are the same page, would you mind to further elaborate on "reference documents for configuration settings details for speed negotiation using ALTGX_RECONFIG"?
For example, what is the configuration settings details that you are referring here?
Just wonder if you have looking for some documentation which discuss about rate change for SATA application in SIV devices? If yes, you may try to refer to AN 625 - Implementing SATA and SAS Protocols in Altera Devices (https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/an/an635.pdf) to see if it is helpful to you.
Please let me know if there is any concern. Thank you.
Best regards,
Chee Pin