Texas Instruments' 100Base-T1 (DP83TC811, DP83TC812) and 1000Base-T1 (DP83TG720) Automotive Ethernet physical layers (PHYs) are designed such that same PCB board can be used for either transceiver. While the hardware changes needed to make the swap are listed in the DP83TC811, DP83TG720 Rollover Document application note, there are also necessarily changes to be accounted for in software. This application note acts as a reference guide to point out the appropriate timing flowchart for these devices and distinguish between the necessary timing specifications of each device.