different mbist and logic bist

[soloktanjung]

hi,

im newbies and interested in this area. i've some question.

1- what is the different between mbist and logic bist? is it possible to use this two method simultaneously in the design?

2- from my previous reading, bist can be design at logic level and rtl. what about behavioral level?

correct me if im wrong.

thx a lot bro!
HAIRO

 

[yln2k2]

Hi ,

BIST : Bilt In Self Test

MBIST : Memory Bist
Logic Bist : Bist for Logic testing (Hard Macro testing).

One design can have both .

2) BIST should be synthesizable so that it will go to silicon.

Thanks & Regards
yln

 

[soloktanjung]

hi,

to implement BIST, we insert the algorithm in the specification and then synthesize it?

am i right?

sincerely, i'm confuse about step by step to include BIST in the design process.

thx a lot.
HAIRO

 

[anishrai]

The Memory BIST is comprised of controller logic that uses various
algorithms to generate input patterns that are used to exercise the memory
elements of a design (say a RAM). The BIST logic is automatically
generated, based upon the size and configuration of the memory element. It
is generally in the form of synthesizable Verilog or VHDL, which is inserted
in the RTL source with hookups, leading to the memory elements. Upon
triggering, the BIST logic generates input patterns that are based upon predefined
algorithm, to fully examine the memory elements. The output result
is fed back to the BIST logic, where a comparator is used to compare what
went in, against what was read out. The output of the comparator generates a
pass/fail signal that signifies the authenticity of the memory elements.
Similar to memory BIST, logic BIST uses the same approach but targets the
logic part of the design. The logic BIST uses a random pattern generator to
exercise the scan chains in the design. The output is a compressed signature
that is compared against simulated signature. If the signature of the device
under test (DUT) matches the simulated signature, the device passes
otherwise it fails. The main advantage of using logic BIST is that it
eliminates the need for test engineers to generate huge scan vectors as inputs to the DUT. This saves tremendous amount of test time. The disadvantage is
that additional logic (thus area) is incorporated within the design, just for
testing purposes.

 

[soloktanjung]

ok thanks.

that give me some idea how my project going to be.

regards,
hario

 

[laglead]

I think behavioral level can do