Combine observations when one instrument cannot distinguish the likely causes. Keep the firmware, workload, and target state consistent, and record any reset or halt between measurements.
Pair a log with power
The JS220 UART result contains received bytes without timestamps that align them with current samples. It can confirm which markers arrived during the capture, but cannot establish exact sleep/wake boundaries in the power trace. For current in each state, hold the target in a known state, allow it to settle, and capture each state separately. Use a sampled marker and a suitable timebase when transition timing matters; a separate serial log and power capture do not necessarily share a clock.
Separate protocol and electrical problems
The logic capture checks frames; the scope checks the signal. Use a common marker or trigger if the conclusion requires correlating one exact event across instruments.
Investigate a reset
Check register access rules and the debugger attachment precautions first. Do not clear a status register that still contains useful evidence.
Move from GDB to trace
Save stack and register observations before starting J-Trace coverage or a bounded instruction capture. Those captures reset and run the target and can stop existing GDB or RTT sessions.
Treat the paused debugger observation and the later trace as separate runs.
Make the test repeatable
Ask Embedder for one hardware script containing the setup, ordered actions, pass condition, and cleanup. Keep longer investigations in a case with the raw captures and findings.
Record:
- Firmware artifact and board revision.
- Wiring, supply, channels, trigger, and achieved sample rate.
- Reset, halt, or other actions that changed target behavior.
- The observed result and what it does or does not establish.
Stop active captures when finished so the next hardware task can run. Last modified on September 12, 2026
