There are several tools to help facilitate the prototyping and testing process for embedded systems. These include test extenders, load boards, and SerDes test modules.

Let’s first look at the extender board. It extends the signals of the loaded card outside of the card cage for easier testing/debugging. This tool is particularly necessary when cards that are side-by-side need to be tested. Bustronic offers these extenders in VME/64x, VXS, MTCA, ATCA, and cPCI form factors. Even a VPX version is possible. VXS and VPX do not have standard right angle male connectors available. So, a rigid-flex-rigid layout is one way to overcome this problem. (See Diagram #1)

Diagram 1

Load boards help to ensure a system's operating specifications. The load board functions to test a system's cooling capabilities by first applying the load to the power supply for verification and creating the necessary heat to confirm chassis cooling. By locating hot spots in the chassis, a system designer can verify where to optimally redirect the airflow to prevent overheating. Load boards are also now available for newer architectures like MicroTCA. They apply configurable power loads to the chassis, to test how components run at various voltages.

Particularly with the high-speed new architectures, testing the signals is becoming more challenging without investing in expensive equipment. Much of the equipment in labs today, such as oscilloscopes and Time Domain Reflectometers (TDRs), are at least 10 years old. It’s likely that they cannot handle the high speed signals present in new architectures like VPX and MicroTCA. To resolve this, there are now SerDes test modules for architectures like VPX. (See Diagram #2) Plugging into the backplane, the SerDes modules can test various high speed serial interface technologies such as VITA46.3 (SRIO) and VITA46.4 (PCI Express). Eye diag rams and Bit Error Rates (BER) of the signal characteristics can be reviewed to ensure the cards/backplane are working to appropriate performance levels. Therefore, the user can guarantee the performance of the system, backplane, or their line cards. With minor modifications, VXS versions can also be designed. A MicroTCA version is expected to be released from Elma/Bustronic in the summer of 2008.

Diagram 2

The SerDes test modules can be simply plugged into a laptop or desktop computer and be up and running with some simple GUI software loaded. This can be a big advantage. Many labs have their equipment tied up a majority of the time on various projects (if they can even handle the high serial speeds). The Elma Bustronic SerDes test cards make it easy and convenient enough for an engineer to do testing without tying up the human and equipment resources of the test lab. Each test module site can provide 4-16 channels of 100 ohm differential controlled impedance connections.

For more information on Bustronic’s test accessories, visit www.bustronic.com or email us at sales@bustronic.com