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[Feature Request]: Refine connect failure error to indicate missing or undetected target #668
Description
Description
Improve error message when a debug probe is connected but the target is not detected. Currently the pyOCD does not distinguish between a communication error during a debug session and a communication error on connect.
Current message on connect failure:
C SWD/JTAG communication failure (No ACK); check USB cable, reduce debugger clock [__main__]
Proposed message for error on connect failure:
Target not detected. Check connection to target.
Is this request a Security Requirement?
- Yes
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Low
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jreineckearm commentedon Jan 14, 2026
This is only about early DP ReadID, not all DAP accesses.
ReinhardKeil commentedon Jan 14, 2026
I would add the hint to the debug clock speed. Proposed new message:
RobertRostohar commentedon Oct 8, 2026
The original Critical message (C prefix) depends on probe used and also if debug sequences are used.
We should therefore keep that message since it provides more context, convert it to an error (E prefix) and add the critical message "Target not detected" and exit.
This would look like as the following examples:
Basically, the first Error message (E) would be specific, but the second Critical message (C) would be the same indicating "Target not detected."
ReinhardKeil commentedon Oct 8, 2026
@RobertRostohar I believe this is a good solution. Keep it this way.
RobertRostohar commentedon Oct 8, 2026
Implemented by pyocd/pyOCD#2045