Use the following IOP testing procedure:
For the IOP tests measuring link-up time either after power-up or after hardware reset, it is important to start the measurement of link-up time after the initialization configuration is loaded back into DP83TC81x. As the configuration is loaded into the PHY by a controller, we recommend the controller to give an indication (a software bit or an IO state) after the last configuration register is written. This indicator going high is the start of measurement of link-up time.
Link-status is indicated by bit 2 of register 0x1: 1 = link-up; 0 = link-down. This should be polled to indicate the event of link-up or link-down during these tests.