# Flash, reset and view This is the first page in the section that needs hardware: a board with a SEGGER J-Link, which on many Ambiq EVBs is onboard rather than a separate probe. It also needs the J-Link Software and Documentation Pack, so if [`nsx doctor`](https://ambiqai.github.io/neuralspotx/getting-started/doctor/) still reports the SEGGER checks as failures, fix that first. The terminals below are illustrative examples, not captured hardware runs. Probe serial numbers are fictional; the flash example summarizes the sequence in brackets. Actual J-Link messages vary with the software version, board and build state. ## 1. Find the probe `nsx probes` enumerates connected J-Link probes and prints their USB serial numbers. Here is an example with two probes connected: ```text $ nsx probes SERIAL PRODUCT NICKNAME 123456789 J-Link - 987654321 J-Link - ``` With a board attached it lists one line per probe. `--json` gives the same list in machine-readable form. If exactly one probe is connected you never need to name it; with more than one, pass `--probe-serial ` to every command that touches hardware. The serial is printed here and on the probe label. See [`nsx probes`](https://ambiqai.github.io/neuralspotx/reference/cli/probes/). ## 2. Flash ```text $ nsx flash --probe-serial 123456789 [Configure the app and build the firmware] [Connect to the selected J-Link probe over SWD] [Program and verify the firmware image] [Reset the target and start the application] ``` `nsx flash` builds the app if the image is out of date, then drives `JLinkExe` over SWD using the command file NSX generated into `build//jlink/`. Expect the Ninja build lines you already saw from `nsx build`, if anything needed rebuilding, followed by J-Link's own connect, program and verify output, and then a reset that starts the firmware. `nsx flash` takes the same `--board`, `--toolchain`, `--target`, `--jobs`, `--update` and `--frozen` options as `nsx build`, plus `--probe-serial`. :::note[--probe-serial always reconfigures] The probe serial is baked into the generated SEGGER command files, so passing `--probe-serial` forces a reconfigure. `--frozen` changes how the accompanying module sync behaves, not whether the reconfigure happens. ::: See [`nsx flash`](https://ambiqai.github.io/neuralspotx/reference/cli/flash/). ## 3. View ```bash nsx view ``` `nsx view` opens `JLinkSWOViewerCL` against the board's SEGGER device and streams ITM port 0. The app generated by `nsx create-app` prints one line per second from its main loop, so the viewer should settle into a repeating heartbeat: ```text nsx hello from generated app nsx hello from generated app nsx hello from generated app ``` Press Ctrl-C to stop. ### The reset policy Whether the viewer resets the target after it attaches depends on the SoC. NSX resets by default, except on the `apollo3p`, `apollo4l`, `apollo4p` and `apollo510b` SoCs, where a SEGGER reset can halt in the secure boot handoff and drop the viewer. On those boards NSX attaches without resetting and prints a line telling you so, which is why the working order there is `nsx flash` and then `nsx view`: the flash already started the app. Three options override it: - `--reset-on-open` forces the reset. - `--no-reset-on-open` suppresses it. - `--reset-delay-ms` changes how long NSX waits after the viewer attaches before resetting. ### Recording instead of watching - `--duration SECONDS` stops the viewer on a timer instead of running until interrupted. - `--capture FILE` line-streams the output to a file as well as to your terminal. Together they make a viewer run scriptable, which is what CI and benchmark harnesses use. Use `--duration` rather than wrapping the command in `timeout`. On Linux and macOS NSX also stops the viewer if it is sent `SIGTERM`, but `--duration` ends the capture cleanly. See [`nsx view`](https://ambiqai.github.io/neuralspotx/reference/cli/view/). ## 4. Reset on its own `nsx reset` talks to the probe directly, so it takes the SEGGER device name rather than an app directory. ```bash nsx reset --device AP510NFA-CBR ``` `AP510NFA-CBR` is the device the Apollo510 EVB resolves to. Other boards set their own; the value NSX uses for your board appears in the generated `build//build.ninja` as the `-device` argument. `--kind` picks the reset primitive, `debug` or `swpoi`. `--interface` and `--speed-khz` set the debug interface and its speed, and `--verify-reconnect` reconnects afterwards and fails if the target did not come back. See [`nsx reset`](https://ambiqai.github.io/neuralspotx/reference/cli/reset/). ## When it does not work - Nothing listed by `nsx probes`: check the USB cable and that the board is powered, then re-run `nsx doctor` to confirm the SEGGER runtime starts. - Flash succeeds but the viewer shows nothing: on a secure-reset SoC the app may not have been started. Flash again, or pass `--reset-on-open`. - More than one board on the desk: pass `--probe-serial` explicitly rather than letting NSX pick. ## Next [Next steps](https://ambiqai.github.io/neuralspotx/getting-started/next-steps/) points at the guides, the module catalog and the reference.