Configure PHY to Test Mode 2 for the following
tests by setting MDIO registers according to 1000 Base Test Mode 2 in Appendix B.
Note: DP8386x is unable to support providing the
TX_TCLK signal to external pin. Therefore, slave jitter testing cannot be conducted
as a link partner is required for this test. Please make sure the scope is set
accordingly for these configurations when conducting jitter testing.