SWRU455M February 2017 – October 2020 CC3120 , CC3120MOD , CC3130 , CC3135 , CC3135MOD , CC3220MOD , CC3220MODA , CC3220R , CC3220S , CC3220SF , CC3230S , CC3230SF , CC3235MODAS , CC3235MODASF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
Figure 25-17 describes the flow of a command from the host to the device, along with the command complete indication from the device to the host followed by an async event. It also illustrates the behavior as it appears in the sample code provided with the SimpleLink SDK for MSP430 processors.
As seen in Figure 25-17, the communication starts with the host sending the long (8 bytes) SYNC word, followed by the command itself which includes header information and payload (when applicable).
When the command has been analyzed by the device, it asserts the RTS line for the sleep exit transition duration (if was in sleep mode). The device then begins to transmit the command response, which starts with the short (4 bytes) SYNC word, which is suspended by the host flow control RTS line (due to its very small 4 bytes jitter buffer). When the host de-asserts the RTS line, the command response transmission is resumed. Later, the device may enter (if required) again to sleep mode.
The last transmission shown in Figure 25-17 is an independent async event sent by the CC31XX device.