Arm ULINK2
Debug & TraceEntry-level JTAG/SWD debug adapter for Arm Cortex-M microcontrollers, JTAG clock up to 10 MHz, SWO at up to 1 Mbit/s, reliable debug for Keil MDK. Note: ULINK2 is now considered legacy by Arm; new procurement should evaluate ULINKplus or ULINKpro. Buy in India from GSAS with local support.
Interface
JTAG, SWD
Architecture
Arm Cortex-M
JTAG / SWD clock
Up to 10 MHz
Trace
Serial Wire Output (SWO), UART mode up to 1 Mbit/s
Host Connection
USB 2.0
IDE
Keil MDK
Status
Legacy, evaluate ULINKplus / ULINKpro for new projects
Overview
About ULINK2
The Keil ULINK2 is an entry-level debug adapter for Arm Cortex-M microcontroller development, providing JTAG and SWD debug interfaces with Serial Wire Viewer (SWO) output for basic trace and printf-style debugging. ULINK2 is the most accessible debug probe in the Keil ecosystem, offering the core run-control debug capabilities, breakpoints, single-stepping, memory and register inspection, and flash programming, that every Cortex-M development project requires.
ULINK2 supports the standard 20-pin JTAG/SWD connector and works with all Cortex-M devices supported by Keil MDK. The SWO output enables ITM trace for printf-style debug output, exception and event tracing, and basic timing analysis without consuming a UART peripheral. For teams starting Cortex-M development or working on projects where power measurement and ETM trace are not required, ULINK2 provides a reliable and cost-effective debug solution.
ULINK Probe Comparison
| Feature | ULINK2 | ULINKplus | ULINKpro |
|---|---|---|---|
| Debug Interface | JTAG, SWD | JTAG, SWD | JTAG, SWD |
| JTAG / SWD clock | Up to 10 MHz | Higher than ULINK2 | Up to 50 MHz |
| Trace | SWO, UART mode up to 1 Mbit/s | SWV with timestamps | SWV up to 100 Mbit/s (Manchester); ETM up to 800 Mbit/s |
| Power Measurement | No | Yes (integrated current measurement) | No |
| Galvanic isolation | No | Yes (1 kV integrated) | No (separate Isolation Adapter accessory) |
| User I/O pins for test sync | No | 9 user I/O pins | No |
| Code Coverage | No | No | Yes (gcov-format via ETM trace) |
| Memory R/W (download) | Standard | Standard | Up to 1 MB/s (per Arm ULINK Probes Feb 2026) |
| Host Connection | USB 2.0 | USB 2.0 | USB 2.0 |
| IDE | Keil MDK | Keil MDK | Keil MDK |
Why GSAS for ULINK2
GSAS provides ULINK2 debug adapters with hands-on application engineering, Keil MDK setup support, and manufacturer warranty across India, backed by local stock availability and INR procurement. ULINK2 is an excellent choice for university labs, startup teams, and production programming stations where the advanced features of ULINKplus (power measurement) or ULINKpro (ETM trace and code coverage) are not required. Our applications team can help you select the right ULINK probe for your project requirements and walk you through Keil MDK setup and debug configuration on your target hardware.
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Related products
More from Arm
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ULINKplus
Advanced debug adapter with power measurement, test I/O, and SWV trace for Arm Cortex-M development and testing. Available in India from GSAS with hands-on application engineering and local support.
View ULINKplus →
ULINKpro
High-speed debug and trace probe with ETM streaming trace and code-coverage support for Arm Cortex-M, JTAG up to 50 MHz, SWV up to 100 Mbit/s (Manchester), ETM up to 800 Mbit/s, memory R/W up to 1 MB/s per Arm ULINK Probes (Feb 2026). Local stock and support across India, GSAS.
View ULINKpro →
ULINKpro D
Debug variant of ULINKpro for Cortex-M, JTAG up to 50 MHz, SWV up to 100 Mbit/s (Manchester), memory R/W up to 1 MB/s per Arm ULINK Probes (Feb 2026). No ETM trace (use ULINKpro for ETM). India pricing and local support from GSAS.
View ULINKpro D →Interested in ULINK2?
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