Subject: Re: 8051 clock
References: <firstname.lastname@example.org> <email@example.com>
Organization: The Armory
X-Newsreader: trn 4.0-test69 (20 September 1998)
From: firstname.lastname@example.org (Richard Steven Walz)
Date: 08 Oct 2002 02:27:57 GMT
In article ,
petrus bitbyter wrote:
>> >Read again, preferable the whole discussion and don't yell to me. If you
>> >still don't understand, come again. FYI, I build both 8751- and 8031
>> >using the original data books from Intel and Philips.
>> I've built those up for YEARS with the SAME clock, or swapped any of that
>> type for any other with total impunity. What are YOU doing wrong?
>> -Steve Walz email@example.com ftp://ftp.armory.com/pub/user/rstevew
>> Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
>> http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
>Well, I don't. But even if I do there's no reason to yell about it. FYI, I
>repeat the original question below:
>> Well i have problem with 8051 clock,
>> i had connected the 2 small capacitors ~15nP but still no clock,
>> BUT , when i'm taking the 8051 out from the circuit and connecting
>> those caps with the vcc,GND i can see the clock as it should be.
>> my circuit is simple 8051,74373 and eeprom(at28c64), how can the
>> circuit cause me to loose the clock..?? (i check all the connections
>> the relevan to the clock)..
>> Please your advice,
>> Eitan Herman.
>Having so much experience, you will admit that you may run into
>unpredictable problems using a 8051 in a board that has not been designed
>for it, *unless* you pull the /EA pin, to inhibit the internal ROM making
>the 8051 behave like a 8031 as Spehro Pefhany added.
I use a berg jumper and a pull-up on pin 31 for all MY boards!
But that's unrelated to the clock question.
P.S., I'm not yelling, that's just an emphatic stylization.
>So there never has been a point about the absence of a clock circuit in a
>8051-family processor until *you* thought it was.
You can pop any 40-pin 8031/51/32/52 and have it work in an 8031
application if you pull pin 31 low.
-Steve Walz firstname.lastname@example.org ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public