Cause of Metastability and It's Solution for it's Removal

[spartanthewarrior]

metastable correct

Hi All,

Can any body tell me

1) Possible Causes of Metastability

2) Solution of it's Removal

 

[varunvats69]

Re: Cause of Metastability and It's Solution for it's Remova

1) Possible causes of metastability:
i. Slow transition times (rise and fall times) at the input of devices, which could in turn possibly be due to a low VDD, high parasitic capacitance and cross-talk. Also do check the formula for rise and fall times, it could be a pointer to other factors.
ii. Cross-talk - an aggressor may cause a neighboring net to go into the undefined region, leading to a metastable output.

2) For slow transition times, buffer up the nets (if cross talk is the reason) or reduce IR drop (if low VDD is the reason) and space out the nets (if parasitic caps is reason). Again, there are many more ways to deal with each of them individually.

Do correct me if anything seems out of place.