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What is the major problem faced in DFT with tri-state buffer

Posted: Wed Apr 09, 2014 10:31 pm
by Arvind
What is the major problem faced in DFT with tri-state buffers and how is it resolved?

Re: What is the major problem faced in DFT with tri-state bu

Posted: Mon Apr 14, 2014 6:06 pm
by RENU
Tri-state buffers are generally used for bidirectional IO's or to drive sharing buses . Chip Select (CS) of memories is an example. Tri-state buffer can be represented as : bufif0(PAD , I ,OEN) , bufif1(PAD , I ,OEN) .

Issues with tri-state buffer :-

1. Probability of contention :- Bus contention occurs when two drivers forces opposite value onto tri-state bus.
2. Output as High -Z :- If tri-state buffer select line is not controlled properly then it can result output in high -Z state and hence effectively removing the output from the circuit.

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