28 Jun
2001
28 Jun
'01
4:30 p.m.
Well, the question is "how worried about ringing *should* I be in a
single backplane configuration if I use bus drivers which have a
rise/fall time of 9 ns, when the bus spec says that the rise/fall
time of bus drivers must not be *less* than 10 ns?"
I'm guessing that it will probably be OK, but I really want this
thing to "work first time" and be reliable so I feel a little
uncomfortable cutting corners like this right at the outset.
Chuck McManis wrote:
Generally faster rise times are better unless you're worried about ringing.
It will enhance your setup and hold times and thus make your card more
reliable on the end of the bus...
--Chuck
At 08:29 PM 6/28/01 -0700, you wrote:
>I was tempted to use a pair of DS3862 octal bus transceivers since
>I want an internal tri-state bus on the card, but it looks as if
>the rise and fall times on the drivers are just a little fast
>(nominal 9ns compared to a minimum of 10ns according to the qbus spec).