SWRA466E February 2015 – August 2024 CC1310 , CC1310 , CC1311P3 , CC1311P3 , CC1311R3 , CC1311R3 , CC1312PSIP , CC1312PSIP , CC1312R7 , CC1312R7 , CC1314R10 , CC1314R10 , CC1352P , CC1352P , CC1352P7 , CC1352P7 , CC1352R , CC1352R , CC1354P10 , CC1354P10 , CC1354R10 , CC1354R10 , CC2538 , CC2538 , CC2620 , CC2620 , CC2630 , CC2630 , CC2640 , CC2640 , CC2640R2F , CC2640R2F , CC2640R2F-Q1 , CC2640R2F-Q1 , CC2642R , CC2642R , CC2642R-Q1 , CC2642R-Q1 , CC2650 , CC2650 , CC2650MODA , CC2650MODA , CC2651P3 , CC2651P3 , CC2651R3 , CC2651R3 , CC2651R3SIPA , CC2651R3SIPA , CC2652P , CC2652P , CC2652P7 , CC2652P7 , CC2652PSIP , CC2652PSIP , CC2652R , CC2652R , CC2652R7 , CC2652R7 , CC2652RB , CC2652RB , CC2652RSIP , CC2652RSIP , CC2674R10 , CC2674R10
The CC2538, CC13xx, and CC26xx bootloader uses the same format for receiving and sending packets. The actual signaling on SPI and UART transportation layers is different, but the packet format remains the same. Table 2-7 shows the packet format and each field is described in Table 2-8.
| Size (1 Byte) | Checksum (1 Byte) | Data byte 1 | … | Data byte N |
| Packet Field | Size (bytes) | Description |
|---|---|---|
| Size | 1 | The number of bytes in the packet, including the size byte. |
| Checksum | 1 | The checksum of the data. The checksum algorithm is the sum of
the data bytes truncated to 8 bit. Checksum = (∑data) mod 256 |
| Data | 1–253 | The actual data bytes. The first data byte is typically the command byte of the bootloader. |
Packet send and packet receive must adhere to the simple protocol shown in Figure 2-2. Both the host device and the CC2538, CC13xx, or CC26xx bootloader can act as sender and receiver. The host device becomes the receiver when the device waits for a data response from the bootloader.
For more details about the communication protocol, see references 1 through 6 in the References section (also listed in Section 2).
Figure 2-2 Sequence
Chart for Send and Receive Protocol