Unibus / Qbus bus drivers and receivers

From: Michael Davidson <michael_davidson_at_pacbell.net>
Date: Thu Jun 28 23:30:58 2001

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).
Received on Thu Jun 28 2001 - 23:30:58 BST