[Diy_efi] Re: looking for help with a prom N82S181

Ludis Langens ludis at cruzers.com
Sat Nov 13 08:12:54 GMT 2004

mbelloli at speedymotorsports.com wrote:
>      Ludis, I'm following you.  Now looking at that waveform trace it
> never reaches ground, nor vcc.  When is the logic true?  This is what
> I'm not following.  Is there a voltage threashold that needs to be
> considered?  Something like the o2 voltage on a gm car crossing the
> .42 volt threashold?

For TTL logic, the spec is that anything below 0.8v is a "0" and
anything over 2.0v (or is it 2.4v?) is a "1".  With MOS (CMOS, NMOS,
PMOS) chips, the levels can be closer to the power supply rails,
however, many MOS chips have adapted the TTL levels for compatibility.

Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
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