Вот этим я пользовался, но, как я понял, оно лежит именно в ROM RF
Core: Through a dedicated IEEE radio API, the RF Core supports the 2.4-GHz IEEE 802.15.4-2011 physical layer (2
Mchips per second Offset-QPSK with DSSS 1:8), used in Thread, Zigbee, and 6LoWPAN protocols. The
802.15.4 PHY and MAC are in radio and system ROM. TI also provides royalty-free protocol stacks for Thread
and Zigbee as part of the SimpleLink SDK, enabling a robust end-to-end solution.