New TM4C129x devices with integrated Ethernet Controllers are available in different configurations so that a user can pick the device that best fits for their application and cost point. Texas Instruments has devices with integrated PHY, and also with MAC only option which provides the user with the flexibility to pick and choose an external PHY as needed. Integrated MAC only devices are available with MII or reduced MII interfaces. In either case, the system clock should be at least 20 MHz if the user is using the MAC, and an external 25 MHz clock source is required if using the integrated PHY.