Re: SRAM undershoot and IBIS models

Syed Huq wrote:
>
> IBISgurus:
>
> In many SRAM datasheets, they have a 'Undershoot Voltage' spec that looks
> like this:
>
> Vih________
> \
> \
> \ /\ ___________ Vss
> \ / \ /
> \ / \/
> ---------------------
> |\ /|
> | \/ |
> --------------------- Vss - 1.0V
> ---->| |<---
>
> "20% of Cycle time"
>
> Question:
> ---------
> 1) Can this be modeled in IBIS ? if yes, by using which keyword ?
>
> If the cool ASCII drawing got messed up by your mail system, refer to
> Motorola SRAM databook for MCM63F737K/MCM63F819K.

Syed, how do you DO it? This very question came up in last week's
JEDEC JC-42 meeting. They're trying to write overshoot specs into
new standards but since this is a lifetime degradation issue there
MUST be something to enable duty-cycle limitations, which are
presently not supported in IBIS.

-- 
D. C. Sessions
dc.sessions@vlsi.com