RTL Logic

From: Jim Battle <frustum_at_pacbell.net>
Date: Sun Jan 9 05:50:58 2005

der Mouse wrote:

>>Wired-OR will work fine for open-collector output TTL.
>
> Well, except you generally get wired-AND, because the open collectors
> are generally NPN collectors with emitters to ground, not PNP
> collectors with emitters to Vcc.

That is twice you've tried to make this point. If a signal is viewed as
active low, then what is going on is logically wired-or. Imagine an
active low reset signal with two open collector drivers on it. If
either or both drivers pull down, then reset is activated. OR in this
case, not AND.
Received on Sun Jan 09 2005 - 05:50:58 GMT