Pinout for MCU-Link Pro to LPC832 in CMSIS-DAP debugging

[aaronm]

Hi.  I'm using a free-standing LPC832 - not part of any EVK - and the SWD connections as referenced in *1 work fine if I'm using the J-Link debugger.  However, if I debug with LinkServer and the MCU-Link Pro, with the same pin connections, I get the following:

02: Failed on Connect
Target marked as not debuggable.
Probe(0): Connected&Reset
Remote communication error. Target disconnected.: Connection reset by peer.

Does the stand-alone LPC832 not support CMSIS-DAP debugging?  Are my pins connected incorrectly?  I could flash the MCU-Link Pro with Segger firmware and use it as another J-Link debug probe, but I'd rather have two types of probes.

Thanks

*1: https://community.nxp.com/t5/LPC-Microcontrollers/Pinout-and-debugger-configuration-for-reliable-SWD...

[aaronm · Accepted solution]

I figured it out: the TDO pin needs to be connected for CMSIS-DAP debugging.  Evidently, this is not necessary with J-Link debugging - as I've experienced in actual practice.  The MCU-LINK Pro schematic helped.  See page 4, "Cortex Debug (SWD/JTAG) interface."

https://www.nxp.com/downloads/en/schematics/MCU-LINK-SCH.pdf

[frank_m]

Some debug probes have configurable options to enable/disable the 3.3V supply to the target through the debug adapter.
Perhaps this is your problem ?

[brendonslade]

Good point, but MCU-Link (base model) cant power a target. MCU-Link Pro can.