5.3.1 Step 1: Target Connection

Before commands can be sent to the device, it must go into bootloader mode. The procedure for connecting to the target in bootloader phase follows:

1. Flush the UART RX line (CC3120 or CC3220 UART TX line).
2. Send a break signal (sending continuous spacing values, no start or stop bits) on the CC3120 or CC3220 UART RX line. The CC3120 or CC3220 device must sense this break signal during power up.
3. Power on the device (or reset it if it is already up and running).
4. The CC3120 or CC3220 device sends an acknowledgment indication. The acknowledgment indication is described in Ack.
5. On receiving the acknowledgment indication from the CC3120 or CC3220 device, the main processor stops sending the break signal and flushes the UART lines.

NOTE

At this point, the CC3120 or CC3220 device is ready to receive any command. The main processor has 5 seconds to send any command. Failing to do so before the time-out expires results in the CC3120 or CC3220 device initializing normally (aborting bootloader mode).

6. The main processor sends the Get Storage List command.
7. The CC3120 or CC3220 device responds with an Ack followed by a 1-byte storage list bitmap.

Figure 3 shows the Get Storage List command.