SWRU455M February 2017 – October 2020 CC3120 , CC3120MOD , CC3130 , CC3135 , CC3135MOD , CC3220MOD , CC3220MODA , CC3220R , CC3220S , CC3220SF , CC3230S , CC3230SF , CC3235MODAS , CC3235MODASF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
The SimpleLink Wi-Fi device supports a standard UART interface with a hardware flow control (RTS/CTS). The default baud rate is 115,200 bps and can be increased to 3 Mbps. Table 4-3 lists the required UART settings.
Attribute | Value |
---|---|
Baud rate | 115,200 bps
(can be increased to 3 Mbps) |
Flow control | CTS/RTS |
Parity | None |
Data bits | 8 |
Stop bit | 1 |
Figure 4-2 shows a typical host setup of the SimpleLink Wi-Fi device using UART interface.
Working with the UART interface requires the use of hardware flow control to avoid data loss. UART hardware flow control works because an entity that is ready to accept data keeps its RTS line asserted. Before the transmission, the UART peripheral of the second side will read its CTS line, which is connected to the RTS of the first side, to verify if it is allowed to send data over the line. The SimpleLink Wi-Fi device may request to stop transmissions in some scenarios; and therefore, its RTS line must be respected. If the host is fast enough and does not need to stop transmissions from the SimpleLink device at any time, the CTS line of the SimpleLink Wi-Fi device might be tied to a pullup instead.
For UART mode only, the following define should be added in user.h: #define SL_IF_TYPE_UART
For more details about the UART interface, refer to Section D.