DP83TC813S-Q1: The dp83tc813 chip cannot operate

Part Number: DP83TC813S-Q1


We read all the registers of the PHY chip and all the values are 0xffff.  

DP83TC813R-Q1: DP83TC813R-Q1 Register 0x2 value read 0xFFFF via MDIO lines - Interface forum - Interface - TI E2E support forums  

We looked at this link, but it doesn't work.

We have confirmed that a 50 MHz clock is coming into XI. ( Has power, has reset )