On Sun, Nov 11, 2007 at 03:48:40PM -0500, Timothy Normand Miller wrote:
> On 11/11/07, Attila Kinali <[EMAIL PROTECTED]> wrote:
> > I personaly do not like the "negation bar" in source code
> > as i either use positive logic (there is no need for negative
> > logic within a synchronus design) or have few explicit signals
> > for which it is clear by their name that they are negative logic
> > (which are at the interfaces to the outside world only anways).
> 
> Let me expose for a moment my ignorance of some of the analog aspects
> of digital circuit design.  What is the primary reason for so many
> negative logic signals?  My best guess is that one of the logic levels
> draws more current, but I'm probably going down the wrong track.

Isn't it mostly reset that is negated? There the problem is that on
power on when your power slowly comes online, how would you be able to
drive it high? It's much simpler to keep it to low, all you need if
you're lazy is a capacitor and a resistor.
I'm not so sure about e.g. interrupts, but I'd assume that it might be
because interrupt lines usually have a pullup/pulldown resistor, so your
drivers must work against additional load, and driving a line low
against a load seems to be easier.

Greetings,
Reimar Döffinger
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