probe-rs doesn't work with LPC55S69

[chungae9ri]

Hi,

I am trying to use probe-rs.

When I run probe-rs list, I can see a jlink connection listed as below.

[0]: J-Link -- 1366:0105:000720762184 (J-Link)

But if I run below command to flash my rust binary,

probe-rs run --chip LPC55S69JBD100 --speed 1000 target/thumbv8m.main-none-eabihf/debug/lpc55s69

I got following error.

Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
Running `probe-rs run --chip LPC55S69JBD100 --speed 1000 target/thumbv8m.main-none-eabihf/debug/lpc55s69`
Error: Connecting to the chip was unsuccessful.

Caused by:
0: An ARM specific error occurred.
1: Error using access port FullyQualifiedApAddress { dp: Default, ap: V1(0) }.
2: Failed to read register DRW at address 0xd0c
3: An error occurred in the communication with an access port or debug port.
4: Target device responded with a FAULT response to the request.

But I can use my MCUxpression jlink debugger w/o any issues.

How can I use probe-rs with LPC55S69 EVK?

[ErichStyger]

I did use the LinkServer MCU-Link debug probes sucessfully with probe-rs.

https://mcuoneclipse.com/2024/03/17/nxp-mcu-link-for-rust-with-probe-rs/

https://mcuoneclipse.com/2025/10/15/getting-started-with-rust-on-nxp-lpc55s69-evk/ 

But I used it as CMSIS-DAP probe (not with the SEGGER firmware).

The SEGGER firmware is OEM and has restrictions of use, so probably this is the issue.

Can you try it with the default CMSIS-DAP firmware?

I hope this helps,

Erich

[Harry_Zhang]

Hi @chungae9ri 

MCUXpresso IDE works normally with the same hardware.

This issue is likely due to SWD speed, the target not being held in reset, or another J-Link process still running.

The recommended steps are to close all J-Link servers, reduce the SWD speed.

BR

Harry