ULINKpro

The Arm ULINKpro is the top-tier debug-and-trace adapter in the Keil ecosystem, providing ETM streaming trace via a 4-bit parallel trace port (up to 800 Mbit/s) for non-intrusive cycle-accurate instruction trace on Arm Cortex-M microcontrollers. SWV runs at up to 100 Mbit/s in Manchester-encoded mode for higher-throughput data-trace capture compared to the legacy UART-mode SWO on ULINK2. Run-control JTAG operates at up to 50 MHz; memory R/W (flash download) is rated at up to 1 MB/s per Arm’s published ULINK Probes specification table (Feb 2026).

ULINKpro supports the structural coverage workflows used in IEC 61508 / ISO 26262 / DO-178C tool-qualification efforts: the probe captures ETM trace from the running target; the coverage analyser (e.g. Razorcat TESSY, LDRA, or VectorCAST) consumes the trace and emits the qualified coverage evidence. Note: the probe itself is not safety-qualified, qualification flows through the analyser that processes the trace. Arm publishes coverage output in gcov format (statement, branch); MC/DC coverage is produced by the downstream analyser, not directly by ULINKpro.

Key Features

Feature	Specification
Trace Type	ETM streaming trace (continuous, non-intrusive)
Trace Port	4-bit parallel TPIU, up to 800 Mbit/s
SWV	Up to 100 Mbit/s (Manchester encoding)
JTAG clock	Up to 50 MHz
Target clock	Up to 200 MHz
Host Connection	USB 2.0
Memory R/W (flash download)	Up to 1 MB/s (per Arm ULINK Probes Feb 2026)
Coverage output	gcov-format (statement, branch); MC/DC produced by external qualified analyser
Debug Interface	JTAG and SWD
Target Architecture	Arm Cortex-M

ULINKpro vs ULINKplus

ULINKpro and ULINKplus serve different needs within the Keil MDK ecosystem. ULINKpro is the right choice when your project demands ETM instruction trace, coverage data feeding a downstream qualified coverage analyser, or long-duration trace capture for timing analysis and defect reproduction. ULINKplus is the better fit when power measurement, 1 kV galvanic isolation, and hardware-in-the-loop test I/O are priorities, such as IoT and battery-powered device development where correlating energy consumption with code execution is essential. Teams working on safety-critical Cortex-M firmware typically choose ULINKpro paired with a TÜV-qualified analyser (TESSY / LDRA / VectorCAST) for their structural-coverage evidence; teams optimising power profiles and validating hardware integration choose ULINKplus. Both are available from GSAS with local stock, INR invoicing, and application support.