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Re: Adt(pro)
In article
<9be03592-b7e7-453e-9337-cec4245d884c@a18g2000pra.googlegroups.com>,
David Wilson <mcs6502@gmail.com> wrote:
> On Sep 19, 10:15�pm, "John B. Matthews" <nos...@nospam.invalid>
> wrote:
> > Also, my table was wrong. I had incorrectly indicated that clearing the
> > low nibble of the control register specified an external clock, which is
> > actually specified in bit four. I think I fixed it:
> >
> > <http://home.woh.rr.com/jbmatthews/ssc.html#tbl3>
>
> Bit 4 is the RECEIVER Clock Source selector. The transmitter always
> uses the internal Baud rate selected by bits 3..0.
>
> The foot note indicating that 115200 is only the case if you have a
> standard 1.8432MHz crystal applies equally to the other 15 speeds. The
> 6551 was designed generate a range of standard baud rates only if
> supplied with a 1.8432MHz clock.
>
> My Rockwell data sheets indicate 400ns (2.5MHz) as the clocking limit
> for both the 6551 and 65C51 parts.
Excellent! My source has been tables in Leventhal's _6502_Assembly_
Language_Programming_ and elsewhere on the net. These tend to aimed at
programmers, often eliding interesting engineering data. I always like
to validate the info as best I can, so I appreciate your comments.
--
John B. Matthews
trashgod at gmail dot com
home dot woh dot rr dot com slash jbmatthews