What is Boundary-Scan?
The trend towards dense packaging such as micro-BGA makes the use of boundary-scan inevitable. At the same time, there are many welcome benefits which can dramatically reduce costs in development, production and field service. The links to the right describe various uses of boundary-scan and outline the tools available today for supporting boundary-scan technology.

In our Corelis section, you can find details of particular products, but if you are new to the technology, why not find out a little more by browsing this section, and then contact one of our experts for a detailed discussion, without obligation.

JTAG for Debug and Functional Test
In many microcontrollers, the JTAG pins have a secondary function, usually referred to as JTAG debug mode. In this mode, the pins are not used for boundary scan, but instead as a high speed serial bus to access the on-chip debug engine of the CPU.

This means that JTAG probes or emulators can be used by the development engineer as part of a microprocessor development system.

However, this facility can also be potentially harnessed by the production test system to download programs to the microcontroller on the board in order to have it perform live functional testing. One obvious application is full-speed system memory testing, but in practice a wide range of tests can be implemented. The new ScanExpress JET from Corelis is the first tool to make functional test alongside boundary scan testing possible.

Now find out more about the Corelis JTAG tools...