Data Sheet
Table Of Contents
- 1. Feature List
- 2. Typical Applications
- 3. Design Guidelines
- 4. Pin-Out Description
- 5. Power Control
- 6. Interface
- 7. Antenna
- 8. Bluetooth® Software Stack
- 9. Host Interface
- 10. Connection Examples
- 11. Electrical Characteristics
- 12. RF Characteristics
- 13. Packaging Specifications
- 14. Soldering Recommendations
- 15. Tape and Reel Packaging
- 16. Certifications
- 17. Ordering Guide
- 18. Revision History
3.4 Firmware Updating Related Recommendations
To enable firmware updating an external UART interface connection as shown in Figure 3.2 Example: BT122 Firmware Update via
UART Connections on page 7 is mandatory. BT122 firmware can be updated through the UART interface by holding the host MCU
in reset state which typically will free the UART lines to be used by the update interface.
UART_CTS
CTS
RESET
RST
UART_RTS
RTS
UART_RX
RX
UART_TX
TX
U2
MCU
UART_CTS
CTS
RESET
RST
UART_RTS
RTS
UART_RX
RX
UART_TX
TX
J1
FW Update Interface
VIN
IN
3V3
OUT
U1
LDO
PF4/UART_RX
10
VDD
17
PC8/UART_CTS
6
PC9/UART_RTS
7
PF5/UART_TX
9
UUT1
BT122
VCC
Figure 3.2. Example: BT122 Firmware Update via UART Connections
Another way to update BT122 firmware is used J-Link programmer. In this case SWD debug interface is used. Figure 3.3 BT122 Firm-
ware Update via J-Link Debugger and SWD Interface on page 7 presents pinout connection for proper work of programmer.
PF2/SWO/TDO
12
GND
13
PF1/SWDIO/TMS
14
PF0/SWCLK/TCK
15
RESET
16
VDD
17
UUT1
BT122
GND
GND
RESET
RST
SWCLK/TCK
SWCLK
SWDIO/TMS
SWDIO
SWO/TDO
SWO
VTARGET
V1
U1
J-Link programmer
+3V3
GND
Figure 3.3. BT122 Firmware Update via J-Link Debugger and SWD Interface
BT122 Data Sheet
Design Guidelines
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