Brian Bailey, editor of EETimes’ EDA Designline, recently
penned a blog questioning the ubiquity and value of embedded instrumentation
within chips. It’s a fascinating and timely read, and I’d like to put my two
cents worth in…
In http://www.edn.com/electronics-blogs/other/4394605/Is-there-a-market-for-on-chip-instrumentation,
Brian Bailey observed that over the last few decades, bench test equipment such
as logic analyzers, oscilloscopes, and in-circuit analyzers have moved inside
chips. ASSET has coined the term “embedded instrumentation” for this category
of technology, and our tagline, “Driving Embedded Instrumentation”, describes
our charter to provide value. Our chief technologist of core instruments, Al
Crouch, responded to Brian’s blog by highlighting how ubiquitous embedded
instrumentation actually is. So why did Brian pose the question about its
value?
Well, the one thing that has been glaringly missing is a
common standard for access and control of this embedded instrumentation.
Chipmakers everywhere have been for years embedding tools inside their silicon,
to provide functionality such as temperature/power sensors, memory BISTs,
manufacturing scan chains, etc. etc., but for their own use only. Since
every vendor has done something proprietary, the use of these tools has not
been able to scale when technology from different companies is inserted within
one device, and certainly not to the board-level, where such tools would be
exceedingly valuable.
And this is where the new IEEE P1687 Internal JTAG (IJTAG)
standard, expected to be voted on later this year, comes in. Once widely
adopted, IJTAG will provide a consistent interface to embedded instruments for
characterization, validation, test and debug functions. This will enable a new
universe of low-cost software-based tools which can be used at the chip, board
and system level. Imagine being able to run the same memory BIST during a PCB’s
high-volume manufacturing run as was run when the device itself was fabricated.
Or running a SerDes bit-error rate test using software only while a system is
in an environmental chamber.
For more information on IEEE P1687, as well as some other
interesting standards and projects that ASSET is involved in, see our Standards
Corner.
