SWRU558 June 2020 CC3100 , CC3100MOD , CC3200 , CC3200MOD
Connection to Simple Link CC3x00 devices is applied via standard UART lines. Evaluation boards (either Booster Pack for CC3100 or Launch Pad for CC3200) expose the UART line as VCP via FTDI chipset. FTDI drivers should be installed prior to working with the evaluation board. These drivers are part of the Uniflash installation. It is also possible to work directly with the UART lines.
Regarding the voltage level on the UART lines, it should match the voltage supplied to the device (any IO line is tight to VBAT). Note that an external level shifter may be required if the voltage on the UART line is different than VBAT.
For example, in the Boosterpack evaluation board, an LDO is used to drop the 5 V coming from the USB to 3.3 V (Vref*(1 + R2/R1) = 1.2246 V * (1 + 51K/30.1K) = 3.3 V). In this mode, all IO lines are tight to 3.3 V and the board works in a pre-regulated 3.3 V scheme. In this case, the UART lines used for the tool need to work in 3.3 V as well.