( SNUG 00 Item 20 ) -------------------------------------------- [ 4/05/00 ]
WATER & OIL DO MIX: The SNUG'00 user tool survey numbers for the DFT/ATPG
market may not seem odd at first:
Synopsys DFT Tools ############## 28%
Synopsys ATPG Tools ############# 26%
Mentor DFT Tools ########## 20%
Mentor ATPG Tools ######## 16%
LogicVision Memory BIST ###### 13%
LogicVision BIST #### 9%
Mentor BIST ### 6%
until you realized that the Dataquest numbers for 1998 had Synopsys owning
94.4 percent of the test-chain-insertion market and Mentor owning 94.6
percent of the ATPG market! This SNUG'00 survey data indicates a very
dramatic shift in that market in just 2 years. Is TetraMax *that* good?
For comparison, in the 1998 BIST market, LogicVision held 59.5 percent
and Mentor 27.7 percent -- which pretty much correlates to the SNUG'00
tool survey data.
"To date, I have successfully used TetraMax to produce scan vectors
for 4 chips: 2 one-million plus gate ASICs, 1 one million gate ASIC,
and a 600k gate ASIC. Two of these chips are in production & running
vectors while the others are in the proto stage.
Our current scan methodology calls for multiple groups of scan chains
that are scanned independently (i.e. serially as groups) from one
another. This requires that a test tool not look at each scan chain
as identical in terms of its scan requirements. Synopsys has added a
very flexible enhancement to the tool that will pretty much allow you
to do any kind of funky setup you wish when scanning any particular
chain. With Sunrise our only way to do this was by post-processing
and other convoluted procedures. You can probably tell I am pretty
happy about this feature in TetraMax. My only gripe is w/ TetraMax's
vector generation and hopefully it will be addressed soon in an
enhancement. Specifically, TetraMax currently will scan all groups of
chains for each vector, whether or not it is needed. This wastes
tester cycles and has to do with a fundamental algorithm used in most
ATPG tools.
As for performance, TetraMax is extremely fast and produces good
results. I benchmarked it against Sunrise/Testgen last year when
TetraMax was still Beta on a few near-full scan designs for
combinational and fast-sequential vectors. TetraMax managed to
produce roughly equivalent results to Sunrise in about 1/10 the run
time and less setup time! (That was enough to get me converting
over, despite the fact that the code was still Beta at that time.)
Another feature I have found useful is the graphical debugging
abilities of TetraMax. This allows you to view ATPG violations as a
schematic and "browse" the schematic with annotated values for
different stages of the ATPG algorithm. This has been extremely
useful to me and is a very nice change from the sometimes cryptic
outputs of Sunrise. It also can be used to diagnose vector failures
and help zero in on model problems. This is also the one feature
that needs some more work however in that it still occasionally gives
"schematic too big" errors or acts a little flaky. Still very
useable, it just needs some polishing. I'm not complaining too much
though given that this is the first tool I've seen that gives you
this ability, although I think Fastscan may also have some of this
ability.
One final note regarding TetraMax is with regards to its modeling
methods. With TetraMax you can use Sunrise models, Verilog models,
or custom models written by you or the ASIC vendor. This pleases me
to no end. One of the biggest hassles in the past for me has been
obtaining correct "Sunrise" models for cells, something vendors are
often slow to give or something you must come up with yourself. It
was a major pain. With TetraMax you can often just use the Verilog
model (although there are issues here that must be considered).
Synopsys is also adding library validation procedures that should
help identify problems early on before one has a vector to debug on
a big nasty gate model.
I used to abhor test as the ATPG process was just so damn painful.
TetraMax, however, is fast enough and has some really good debugging
facilities so iterations can be done pretty quickly to zero in on
the vector set's true problems. That makes me one happy customer."
- Russell Petersen, ASIC Engineer, Scientific Atlanta
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