Math Coprocessor

D

DAFLY98

Guest
Hi all, I am working on project that requires trig, algebra as well as basic
math functions. I am working with a Pic 16F84A, and I was wondering what type
of math coprocessor would be good to use with this MUC?

Thanks To all
Jeremy
 
"DAFLY98" <dafly98@aol.com> wrote in message
news:20031026153905.14580.00000136@mb-m20.aol.com...
Hi all, I am working on project that requires trig, algebra as well as
basic
math functions. I am working with a Pic 16F84A, and I was wondering what
type
of math coprocessor would be good to use with this MUC?
Click to expand...
You are kidding, right?
 
Subject: Re: Math Coprocessor
From: "Dave VanHorn" dvanhorn@cedar.net
Date: 10/26/2003 12:57 PM Pacific Standard Time
Message-id: <4eKdncnbzvG0qAGiRVn-tw@comcast.com


"DAFLY98" <dafly98@aol.com> wrote in message
news:20031026153905.14580.00000136@mb-m20.aol.com...
Hi all, I am working on project that requires trig, algebra as well as
basic
math functions. I am working with a Pic 16F84A, and I was wondering what
type
of math coprocessor would be good to use with this MUC? "(Correction MCU)"

You are kidding, right?
Click to expand...

No im not Kidding, I am doing a simple project to learn about IC interface,
computations, and basic control. What's so hard to believe?
 
No, I am not Kidding. Whats so hard to belive?
Click to expand...
The economics don't work out that way any more. I haven't seen a math
coprocessor for ages. (I admit I haven't been looking.)

The usual approach would be to use a bigger/faster CPU
and do it in software.

--
The suespammers.org mail server is located in California. So are all my
other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.
 
Hal Murray (hmurray@suespammers.org) writes:
No, I am not Kidding. Whats so hard to belive?

The economics don't work out that way any more. I haven't seen a math
coprocessor for ages. (I admit I haven't been looking.)

The usual approach would be to use a bigger/faster CPU
and do it in software.

I couldn't decide whether he wanted fast, or just fell it would keep the
Click to expand...
CPU too busy.

In the late seventies, coprocessors weren't the well-integrated schemes
we've seen with the 16-bit CPUs. One scheme was to interface a calculator
with the CPU, which wasn't particularly fast but it did give math results
without the programming (or memory space). I'm not sure where one
would get a calculator IC today that isn't a mound of epoxy.

Michael
 
"DAFLY98" <dafly98@aol.com> a écrit dans le message de
news:20031026153905.14580.00000136@mb-m20.aol.com...
Hi all, I am working on project that requires trig, algebra as well as
basic
math functions. I am working with a Pic 16F84A, and I was wondering what
type
of math coprocessor would be good to use with this MUC?

Thanks To all
Jeremy
Click to expand...
If you don't have critic speed constraints then just use a high-level
language that offer the corresponding libraries (pro-basic, c, etc).
If you do have critic speed constraints then I think you have two options :
1/ just use a quicker MCU (powerquicc, etc)...
2/ or spend more time on the firmware in order to use only integer mode code
and look-up tables. As an exemple my small FFT library for 17C/18F PICs
needs only 50ms for a 256-taps real FFT on 16-bits numbers...

I remember that I've read an add for a PIC based "math coprocessor" (linked
through SPI or similar), but just didn't understand what could be the use
for such a product. My guess is that this product no longer exist because
noone could need it...

Friendly yours,

Robert Lacoste - ALCIOM : The mixed signals experts
http://www.alciom.com
 
In article <20031026153905.14580.00000136@mb-m20.aol.com>, dafly98
@aol.com says...
Hi all, I am working on project that requires trig, algebra as well as basic
math functions. I am working with a Pic 16F84A, and I was wondering what type
of math coprocessor would be good to use with this MUC?

Thanks To all
Jeremy

What everybody is giggling about is that the request is VERY stange. If
Click to expand...
you need to get complex math functions done in a few clock cycles change
the MCU to something a little better suited to doing math quickly. If
speed is not the problem, but coding is, try looking for a math library
to do what you need. I'm sure there is tons of source code out there
for doing complex math with a PIC. It is going to take hundreds or
thousands of clock cycles to do some functions, but you can always run
the puppy at 20MHz and use raw horsepower to compensate for a lot. You
can also code in a higher level language that has libraries for complex
math functions and floating point "built in".

Jim
 
DAFLY98 wrote:
Hi all, I am working on project that requires trig, algebra as well as basic
math functions.
Click to expand...
There is a *lot* missing here. The first issue is the precision needed.

I am working with a Pic 16F84A,
Click to expand...
You should't. Use a modern/faster/sheaper PIC processor.

and I was wondering what type
of math coprocessor would be good to use with this MUC?
Click to expand...
None that I know about. But there are a lot of example code "out there".

I'd definitly use a 18-series PIC. Much easier to program and a builtin
hardware multiplier.


Jan-Erik.
 
James Beck <jim@reallykillersystems_INVALID_.com> writes:
In article <20031026153905.14580.00000136@mb-m20.aol.com>, dafly98
@aol.com says...
Hi all, I am working on project that requires trig, algebra as well as basic
math functions. I am working with a Pic 16F84A, and I was wondering what type
of math coprocessor would be good to use with this MUC?

What everybody is giggling about is that the request is VERY stange. If
you need to get complex math functions done in a few clock cycles change
the MCU to something a little better suited to doing math quickly.
Click to expand...
I'd love to see his schematic using a 486DX2/66 as a coprocessor to handle
the math for his 16F84A. You could probably buy a 486 cpu today for about
the same price as the PIC. He might be able to get away with a few hundred
bytes of code to wake up the 486 and have it accept some sort of P-code
"commands", use the floating point coprocessor in the 486 and return the
results to the PIC, maybe even bit-bangs it back and forth with a software
uart simulation on both ends.

Now a picture of that working would be worth giggling about!

Or, maybe the PIC opens a Math-Link session to a running Mathematica
kernel, has it do the calculations and returns the results to him!
 
On Sun, 26 Oct 2003 22:42:47, dafly98@aol.com (DAFLY98) rolled up his
sleeves and typed:

No, I am not Kidding. Whats so hard to belive?
Click to expand...
The original HP calculators used 4 bit micros I believe. It can be
done but I doubt you'll find a maths co-processor you'll have to code
the algorithms for the functions you need. As an exercise, fine, but
for a serious application with a budget and a project deadline, it
would be better to change to a different processor.

--
Jim Backus OS/2 user
bona fide replies to
<jimb><thecirclethingy><jita><dp><demon><dp><co><dp><uk>
 
http://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=pic+math+coprocessor


"DAFLY98" <dafly98@aol.com> wrote in message
news:20031026153905.14580.00000136@mb-m20.aol.com...
Hi all, I am working on project that requires trig, algebra as well as
basic
math functions. I am working with a Pic 16F84A, and I was wondering what
type
of math coprocessor would be good to use with this MUC?

Thanks To all
Jeremy
Click to expand...
 
DAFLY98 wrote:
Hi all, I am working on project that requires trig, algebra as well as basic
math functions. I am working with a Pic 16F84A, and I was wondering what type
of math coprocessor would be good to use with this MUC?

Thanks To all
Jeremy
Click to expand...
What is a Pic 16F84A?

What is a MUC?
 
What is a Pic 16F84A?
Click to expand...
Think of the microcontroller equivalent of a 8088.


Wouter van Ooijen

-- ------------------------------------
http://www.voti.nl
PICmicro chips, programmers, consulting
 
DAFLY98 wrote:
Subject: Re: Math Coprocessor
From: "Dave VanHorn" dvanhorn@cedar.net
Date: 10/26/2003 12:57 PM Pacific Standard Time
Message-id: <4eKdncnbzvG0qAGiRVn-tw@comcast.com


"DAFLY98" <dafly98@aol.com> wrote in message
news:20031026153905.14580.00000136@mb-m20.aol.com...
Hi all, I am working on project that requires trig, algebra as well as
basic
math functions. I am working with a Pic 16F84A, and I was wondering what
type
of math coprocessor would be good to use with this MUC? "(Correction MCU)"

You are kidding, right?

No im not Kidding, I am doing a simple project to learn about IC interface,
computations, and basic control. What's so hard to believe?
Click to expand...
Hello,

Maybe a older Intel 8087 math coprocessor in a 40 pin package..

Regards
Dan Mathias
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