There are some times requirements to add an Ethernet connection to a device that doesn't have an internal Ethernet controller (as the K50, K60 and 70 devices do). In some situations a second physical Ethernet port is also required to be added to a Kinetis with internal Ethernet too.
The following show two cases:
where a SPI based ENC424J600 has been connected to the mini-Teensy boards with K20 and KL26 parts, showing how Ethernet TCP/IP functionality can be added.
Since the TCP/IP stack is in SW it has not restrictions and is cheaper that typical HW based solutions that are sometimes added in such circumstances.
The same can also be added to parts such as the K64 (eg. to the FRDM-K64F) to turn it into a multi-homed networking device. In this sitation the TCP/IP stack handles IP checksums in software when the ENC424J600 interface is used but still allows the checksum offloading capabilities of the Ethernet controller in the Kinetis device to be utilised when frames arrive from or are sent to this interface.
The ENC424J600 is supported in the uTasker project for all KE, KL, KV or K parts with SPI and adequate Flash/RAM for the TCP/IP rquirements (64k Flash and 16k RAM recommended) as well as for an additional Ethernet interface for K devices with their own internal Ethernet controllers (including multiple-networking, bridging and gateway operation).
Kinetis: µTasker Kinetis support
For the complete "out-of-the-box" Kinetis experience and faster time to market