ST UM2967 User Manual

12.14 SWD debug/program/trace and JTAG/USART
The SWD debug/program/trace interface is accessible through the STLINK-V3E USB connector (CN5) by default,
and debug connector (CN11) or Tag‑Connect
™
10‑pin footprint (CN3) are other options.
By default, access to SWO trace and JTAG is not functional and needs hardware modification.
USART1 bootloader is accessible through STLINK-V3E by default.
To debug/program/trace, first, choose any of the exclusive following connectors, and consider Table 20 to
summarize STM32U5A9J-DK capabilities:
Table 20. Debug/program/trace and JTAG/USART interface overview
Connector
SWD debug/program
SWO trace
(1)
JTAG
(1)(2)(3)
USART1 bootloader
USB STLINK-V3E CN5 Yes Yes, as option No Yes
MIPI10 debug CN11
(STDC14 as an option)
Yes Yes, as option Yes, as option
No
(4)
TAG footprint CN3 Yes Yes, as option Yes, as option No
1. SWO/JTDO (PB3) can be used by moving SB33 on SB34 (exclusive with SDMMC2.D2).
2. NJTRST(PB4) is not connected to connectors but is accessible on CN9 (exclusive with SDMMC2.D3)
3. JTDI is connected by default, and cannot be used when UCPD.CC1 is used.
4. USART1 bootloader interface is only accessible on the CN11 footprint on pin 13/14 of the CN11 footprint: USART1_RX
(PA10) and USART1_TX (PA9). If an STDC14 connector is present on the CN11 footprint, USART will be more easily
connectable.
Refer to Section 12.14.1 and Section 12.14.2 for CN11 and CN3 pin assignment details. When using STLINK-V3E
USB CN5 by default, refer to the software tool description for any specific constraint/capabilities.
12.14.1 User constraints for CN11 or CN3 connectors
Warning: Take care MIPI10 debug and TAG connectors are 1.8 V interface by default, use only
adequate/compatible tools to connect.
Warning: Some TAG connector tools connect a 5V external power on pin 5 of the CN3 footprint which
can create a short circuit. Pay attention to using the right tool combination of adapter/cable
not to bring 5V on pin 5, or simply remove the dedicated solder bridge from PCB, or find a
way to disconnect the 5V signal from your tool.
Warning: The CN11 and CN3 connectors are exclusives, use only one at the same time to avoid
conflict.
UM2967
SWD debug/program/trace and JTAG/USART
UM2967 - Rev 1
page 37/68

ST UM2967 Specifications

General

Brand	ST
Model	UM2967
Category	Computer Hardware
Language	English