Article View: sci.electronics
Article #17570Re: time of year clock chips
From: grr
Date: Wed, 27 May 1987 01:20
Date: Wed, 27 May 1987 01:20
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1820 bytes
In article <16819@amdcad.AMD.COM> phil@amdcad.AMD.COM (Phil Ngai) writes:
>
> I'm designing a CPU board and wondered if anyone could recommend a
> time of year clock chip. Flames about particularly bad or hard to
> program time of year clock chips are welcome too.
>
> Phil Ngai, {ucbvax,decwrl,allegra}!amdcad!phil or amdcad!phil@decwrl.dec.com
The OKI58321 is the low cost leader, but is super slow and needs to be accessed
through some kind of parallel port.
The OKI6242B can interface to a normal microcomputer bus running at normal, but
not blazing speeds and is a good compromise.
Ricoh makes a chip much like the 6242 that includes ~15 bytes of static RAM,
useful for saving configuration or boot up data.
These chips are also available as modules, with battery and/or crystal included,
if the additional cost is a good trade off.
There are lots of other chips available. Watch out for vapor chips and read
the fine print on accessing, battery backup/voltage requirements and glitch/
latchup protection...
--
George Robbins - now working for, uucp: {ihnp4|seismo|rutgers}!cbmvax!grr
but no way officially representing arpa: cbmvax!grr@seismo.css.GOV
Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!utgpu!water!watmath!clyde!rutgers!cbmvax!grr From: grr@cbmvax.UUCP Newsgroups: sci.electronics,comp.unix.wizards Subject: Re: time of year clock chips Message-ID: <1934@cbmvax.cbmvax.cbm.UUCP> Date: Tue, 26-May-87 21:20:58 EDT Article-I.D.: cbmvax.1934 Posted: Tue May 26 21:20:58 1987 Date-Received: Thu, 28-May-87 04:17:22 EDT References: <16819@amdcad.AMD.COM> Reply-To: grr@cbmvax.UUCP (George Robbins) Organization: Commodore Technology, West Chester, PA Lines: 28