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Home > Archive > Unix Programming > May 2004 > Re: [OT] Re: writing a dailer in c for a 8051 based system
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Re: [OT] Re: writing a dailer in c for a 8051 based system
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| CBFalconer 2004-05-30, 10:29 am |
| Malcolm wrote:
> "Dan Pop" <Dan.Pop@cern.ch> wrote in message
> This sounds rather cute. Were these chips used for anything?
No. They ground up millions of them in a wood chipper, and fed
them to the cattle. The results were eventually sold to
McDonalds. Thus mad cows were programmed in Basic.
--
Chuck F (cbfalconer@yahoo.com) (cbfalconer@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!
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| Dan Pop 2004-05-30, 10:29 am |
| In <c92v3v$5s7$1@newsg2.svr.pol.co.uk> "Malcolm" <malcolm@55bank.freeserve.co.uk> writes:
>"Dan Pop" <Dan.Pop@cern.ch> wrote in message
>This sounds rather cute. Were these chips used for anything?
Dunno, I've only seen the specs in an Intel catalog.
Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Dan.Pop@ifh.de
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| David Schwartz 2004-05-30, 10:29 am |
|
"Dan Pop" <Dan.Pop@cern.ch> wrote in message
news:c926pr$k03$8@sunnews.cern.ch...
> In <pan.2004.05.26.09.52.12.812641@sig.now> August Derleth <see@sig.now>
> writes:
[vbcol=seagreen]
> Many older hard disks found in PC's used an 8051 chip, so your definition
> is rather shaky. Furthermore, Intel had an 8052 chip with an embedded
> BASIC interpreter, that could be used as the core of a small computer.
He's saying it's "*designed* to be used in an environment other than a
PC". The 8051 was designed to be embedded in a wide variety of devices, and
not primarily as the central processor of a general-purpose computer.
[vbcol=seagreen]
> This is not the case of the general purpose ones, like the 8051, which
> are best described as single chip computers, containing a CPU, ROM, RAM
> and various external interfaces on a single chip.
Huh? He said it had unboard ROM space and you said it contained "ROM ...
on a single chip". So how is it not the case?
> The word sizes are
> the vanilla ones, so that adding external ROM or RAM can be done using
> cheap, off the shelf, components (no point in having a cheap
> microcontroller if it needs expensive external chips).
You may not be familiar with the 8051, but it's addressing modes were
quite unusual. (If you only programmed it in C, you might not have realized
just how odd it is.) As an example, how many bits do you think you need for
a general purpose pointer in an 8051? (Keep in mind it has code and data in
distinct address spaces.) And what about the external MOV instructions that
take an 8-bit address? Do you know where the other 8 bits of the address
comes from? (It's truly bizarre.)
[vbcol=seagreen]
> Low power consumption is often not an issue (no point in using a < 1 mW
> controller in a microwave oven)
His claim was "often". And he didn't say it was the most important
thing, he said it counted more than clock speed. You aren't seriously going
to argue that clock speed is important in a microwave oven.
So he said A is often more important than B and you came up with a case
where neither is particularly important. How do you think this refutes what
he said?
> but low cost per chip is an overriding
> concern, otherwise the designer would opt for a traditional microprocessor
> + ROM + RAM + I/O intefaces approach, which is often more comfortable to
> program on (the typical CPU in a microcontroller is less capable than an
> usual microprocessor, the program and the data often reside in different
> address spaces, and, for machine code compactness reasons, the program
> memory is often paged).
Well that's the first thing you've said that's correct. Low cost is
quite often the most critical factor in a microcontroller. Though it's not
so much the per chip cost as the cost to implement an entire system. This is
why, for example, a microcontroller is more likely to contain an on-chip
clock generator than a general-purpose CPU is.
DS
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| Alan Balmer 2004-05-30, 10:29 am |
| On Wed, 26 May 2004 21:38:58 +0100, "Malcolm"
<malcolm@55bank.freeserve.co.uk> wrote:
>"Dan Pop" <Dan.Pop@cern.ch> wrote in message
>This sounds rather cute. Were these chips used for anything?
>
Yes. They were and are used for millions of things. That's why Intel
makes so many ;-)
--
Al Balmer
Balmer Consulting
removebalmerconsultingthis@att.net
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| Dan Pop 2004-05-30, 10:29 am |
| In <c92iql$gr8$1@nntp.webmaster.com> "David Schwartz" <davids@webmaster.com> writes:
>"Dan Pop" <Dan.Pop@cern.ch> wrote in message
>news:c926pr$k03$8@sunnews.cern.ch...
>
>
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
^^^^^^^^^^^^[vbcol=seagreen]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^[vbcol=sea
green]
>
> He's saying it's "*designed* to be used in an environment other than a
>PC".
So are plenty of high performance RISC processors, designed to be used in
workstations and servers...
>The 8051 was designed to be embedded in a wide variety of devices, and
>not primarily as the central processor of a general-purpose computer.
See the counterexample mentioned above...
>
>
> Huh? He said it had unboard ROM space and you said it contained "ROM ...
>on a single chip". So how is it not the case?
I was commenting the whole of his statement, not the on-board ROM bit.
See the rest of the paragraph for full enlightenment.
>
> You may not be familiar with the 8051, but it's addressing modes were
>quite unusual.
Having programmed in 8051 assembly, I am reasonably familiar with it and
its addressing modes. I wouldn't say that a word size of 8 bits is
particularly odd...
>(If you only programmed it in C, you might not have realized
>just how odd it is.) As an example, how many bits do you think you need for
>a general purpose pointer in an 8051? (Keep in mind it has code and data in
>distinct address spaces.) And what about the external MOV instructions that
>take an 8-bit address? Do you know where the other 8 bits of the address
>comes from? (It's truly bizarre.)
I'm failing to see the connection between these questions and the size of
the 8051 word. In your humble opinion, why is it called an 8-bit
microcontroller?
>
>
> His claim was "often". And he didn't say it was the most important
>thing, he said it counted more than clock speed. You aren't seriously going
>to argue that clock speed is important in a microwave oven.
If it's not important, then try to control one using a 1 Hz clock...
But my point was that low power is not that often an overriding concern,
while low cost per chip *is*.
If you'd read my sentences and paragraphs in their entirety instead
of interrupting the process at arbitrary points, you might even be
able to see my points by yourself...
> So he said A is often more important than B and you came up with a case
>where neither is particularly important. How do you think this refutes what
>he said?
>
>
> Well that's the first thing you've said that's correct.
Everything I said in my previous post was factually correct. Learn to
read and you may eventually realise it.
Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Dan.Pop@ifh.de
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