Path: utzoo!censor!isgtec!bmw
From: bmw@isgtec.uucp (Bruce M. Walker)
Newsgroups: sci.electronics
Subject: Re: micro-controller
Message-ID: <656@isgtec.UUCP>
Date: 24 Sep 90 17:09:57 GMT
References: <LLEE.90Sep17091114@dopey.uucp>
Sender: news@isgtec.UUCP
Reply-To: bmw@isgtec.UUCP (Bruce M. Walker)
Distribution: sci.electronics
Organization: ISG Technologies Inc. Mississauga Ont. Canada
Lines: 46

In article <LLEE.90Sep17091114@dopey.uucp> llee@rocket.uucp (Leonard Lee) writes:
> Here's what I need:
> 
> - 8 bit CMOS, and with a clock frequency of ~ 3-5 MHz
> - 2 input bits, 4 output bits ( slightly more OK )
> - a small amount of onboard RAM (< 32 bytes)
> - Pin count of <=24 (this is a must)
> - must have a version with EPROM or EEPROM (for prototyping)
> - must have a version with one-time user programmability (for
> low-volume production)
> - low cost (of course!)
> 
> I seem to recall an ad for a few years back about a General Instrument
> microcontroller (PIC or something) that had only 18 pins, but I don't
> know if it is fast enough.  Len

The GI PIC is actually a 12 bit instruction, 4 bit data.  They
come in 18 pin versions.  Take a look inside any BSR X-10 power-line
controller, they all have a CMOS PIC inside.  The instruction set is as
weird as is possible for a human mind to create; that is to say, it
makes a Z80 look orthogonal.  I don't believe they have an E[E]PROM
version, you have to use an expensive development system.

Motorola makes a nice CMOS 6805-family part in a 24 pin package.  Look
for the 1468705xxx where xxx is some string of E's and other upper case
letters.  Pretty sure there's an OTP version now, too.  The instruction
set is a 6800's that has been chopped in half -- literally: one 8 bit
ACC (instead of two), the X register is 8 bits (instead of 16), etc.

Hitachi used to make a better clone of the 6805 called the 6305 and
they came in OTP versions, but I think that Motorola litigated these
out of existance.  Bastards.  Hitachi also makes a litigation-proof
micro with a "different" instruction set; don't know much about these,
but worth checking into.

Zilog makes a really neat teeny-weeny version of the Z8 in an 18 pin
package.  Don't think there's any E[E]PROM version but I could be
wrong, Zilog likes making little hybrids for development purposes.

TI makes the TMS7000 family: looks like they have both EPROM, CMOS and,
I think, small packages (most are 40 pins).

I won't mention Intel (oops) because I hate 'em.

--
bmw@isgtec.uucp  [ ..uunet!utai!lsuc!isgtec!bmw ]  Bruce Walker