Connect to J-Link debugger and start RTT monitoring. Must be called before reading or writing RTT data.

Disconnect from J-Link debugger and stop RTT monitoring.

Read accumulated RTT data from the ring buffer. Data is continuously collected by the background monitor thread. Use this to get output from the target device.

Read the tail of the complete RTT log file. This is an independent broadcast sink (not drained by other clients), so it returns the full RTT output even while another client (e.g. the VSCode extension) is streaming via rtt_read. Prefer this over rtt_read when another consumer is active.

Read new bytes from the broadcast log starting at a byte offset. Non-draining and multi-consumer safe: ideal for a continuous monitor that must coexist with other readers without stealing their data. Pass the returned next_offset as 'offset' on the next call; if the log rotated (next_offset > file size), pass offset=0. Returns JSON: {"data": "...", "next_offset": N}.

Write data to RTT down-buffer (host -> device). The target device must be running RTT with a down-buffer listener.

List available J-Link debuggers connected to the host.

Get current J-Link connection status and RTT buffer information.

Clear the RTT ring buffer. This does not clear the actual RTT buffers on the device.