SWV is a CoreSight component which adds advanced debug facilities to a Cortex-M3 core. The Instrumentation Trace Macrocell (ITM) and Serial Wire Output (SWO) can be used to form a Serial Wire Viewer (SWV). The SWV provides a low cost method of obtaining information from inside the MCU. Serial Wire Viewer uses the SWO pin to transmit different packets for different types of information.

The three sources in the Cortex-M3 core which can output information via this pin are:

• Instrumentation Trace Macrocell (ITM) for application driven trace source that supports print style debugging. It supports 32 different channels, which allow it to be used for other purposes such as real-time kernel information as well.
• Data Watchpoint and Trace (DWT) for real-time variable monitoring and PC-sampling, which can in turn be used to periodically output the PC or various CPU internal counters, which can be used to obtain profiling information from the target.
• Timestamping. Timestamps are emitted relative to packets.

SEGGER J-Link ARM supports all SWV speeds of up to 6MHz on the latest J-Link. Support for SWV completes SEGGER's offering for Cortex-M3 based devices, which already allow accessing the core via JTAG and/or SWD, as well as flash programming solutions.

"SWV support is important for the growing number of Cortex-M3 users. We believe that this is an important step in making sure J-Link stays ahead of the competition.", says Rolf Segger, CEO at SEGGER.

About SEGGER Microcontroller GmbH & Co. KG
SEGGER Microcontroller develops and distributes hardware and software development tools as well as software components. All software components are ANSI "C" compliant and can be used in embedded systems including industries such as telecom, medical technology, consumer electronics, automotive industry and industrial automation. SEGGER software products include: embOS (RTOS), emWin (GUI), emFile (File System), emUSB (USB device stack) and embOS/IP (TCP/IP stack). Besides the highly efficient software products, SEGGER also provides embedded hardware tools such as the well-known JTAG emulator J-Link, J-Trace and the Flasher (stand alone programmer). SEGGER's intention is to cut software development time for embedded applications by offering affordable, flexible and easy-to-use tools and software components allowing developers to focus on their applications.

Contact information:
Mr. Ivo Geilenbruegge
Email: info@segger.com
Phone: +49-2103-2878-0