Version 2.1 communicates to the target through a USB 1.1- and USB 2.0-compatible interface running in high-speed or full-speed modes, providing a 10 times better performance than previous versions.

It features a USB 2.0 full-speed controller and transceiver, SPI controller (enabling communication with SPI slave devices down to 1.8 V), 348-byte programmable memory, crystal-less USB operation ...