co processeor

[pes]

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.


I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?

Thanks for your help

Pes.

 

[Eeyore]

pes wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?

In 100ns !!! ?

Just the time taken alone to transfer the data in and out via the SPI/I2C
interface will take many microseconds.

Graham

 

[Michael Black]

Eeyore (rabbitsfriendsandrelations@hotmail.com) writes:

pes wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?

In 100ns !!! ?

Just the time taken alone to transfer the data in and out via the SPI/I2C
interface will take many microseconds.

But then, he's not really describing a coprocessor, which integrates

will with the CPU and is handling functions by itself.

Michael

 

[PopMed]

On Sep 3, 11:41 am, pes <n...@none.com> wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?

Thanks for your help

Pes.

The chip you mention is much too slow to give you the performance you
need. It is only a math co-processor with a clock speed better suited
for calculators than fast applications. Besides it lacks ADC and
interrupts. To get the speed you want would likely require custom
IC's of the type used to digitize and process video and radar signals
in real time. Assuming you could procure the chips a working system
would cost hundreds of thousands to millions of pounds, dollars, euros
(take your pick).

If you can get by with an arc tangent conversion in 6 microseconds
with a hardware cost of $99 USD I would refer you to an article in
Circuit Cellar issue #202 May 2007. The article of interest is
titled "Proton Precession Magnetometer" by James Koehler. The author
describes a hardware and software solution for measuring the phase
slip angle of magnetically precessed protons in water or kerosene.
Using a $99 Keil evaluation board with an NXP LPC2138 ARM 32 bit
microprocessor running at 60 MHz, two 10 bit ADC, two serial ports,
JTAG (although the USB debugger is an extra cost item) he manages to
collect 8000 10 bit analog samples and perform 2000 arc tangent
calculations in 250 milliseconds. The arc tangent calculation method
is described in the article and employs straight line approximation
along with table lookup trigonometric functions to achieve the 6
microsecond speed mentioned. If you or your library don't have access
to Circuit Cellar you can order a back issue (print or download) or
download for purchase a single article for a few dollars from their
website www.circuitcellar.com

Hope this helps, I'm curious to know the intended application of your
query.

David

 

[pes]

Eeyore a écrit :

pes wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?

In 100ns !!! ?

Just the time taken alone to transfer the data in and out via the SPI/I2C
interface will take many microseconds.

Hi, the serial bus in only intended to setting parameters of the time
which the interrupt will be released according to the angle calculated.

Graham

 

[Fred Bartoli]

Le Tue, 04 Sep 2007 03:22:22 +0100, Eeyore a ĂŠcrit:

pes wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns : (Acquisition of the ADCs,
ArcTang operation and genereate the interrupt). What performance can I
hope ?

What about the MicroMega UM-FPU V3.1 ?

In 100ns !!! ?

Just the time taken alone to transfer the data in and out via the
SPI/I2C interface will take many microseconds.

Uh?

100ns is just 10MHz. These days it's POC.
For ex. AD has the AD9254 and AD9640-150 which are resp. a single and a
dual 150MHz 14b ADC. They also have three 16b >100MSPS ADCs.
They have fifteen 14b ADCs and eight 16b ADCs that fit the > 10MSPS
criteria.
Just stuff the output stream to a small FPGA, let it manage the other
functions too and it's done. Not a big deal really.
The only possible question is the arctan latency. But even 16b accuracy
isn't much at all and a simple table driven + interpolation algorithm
will easily take care of that. Or even a simple dumb 64K size table.

But...
but the OP didn't tell what the ADC resolution has to be, and so on...
This and a lot of details seem to indicate that he's just throwing some
ideas without any understanding of what he's doing and what he really
needs.


--
Thanks,
Fred.

 

[pes]

PopMed a écrit :

On Sep 3, 11:41 am, pes <n...@none.com> wrote:
Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?

Thanks for your help

Pes.

The chip you mention is much too slow to give you the performance you
need. It is only a math co-processor with a clock speed better suited
for calculators than fast applications. Besides it lacks ADC and
interrupts. To get the speed you want would likely require custom
IC's of the type used to digitize and process video and radar signals
in real time. Assuming you could procure the chips a working system
would cost hundreds of thousands to millions of pounds, dollars, euros
(take your pick).

ok, I' m going to looking for other method regards to the price.

If you can get by with an arc tangent conversion in 6 microseconds
with a hardware cost of $99 USD I would refer you to an article in
Circuit Cellar issue #202 May 2007. The article of interest is
titled "Proton Precession Magnetometer" by James Koehler. The author
describes a hardware and software solution for measuring the phase
slip angle of magnetically precessed protons in water or kerosene.
Using a $99 Keil evaluation board with an NXP LPC2138 ARM 32 bit
microprocessor running at 60 MHz, two 10 bit ADC, two serial ports,
JTAG (although the USB debugger is an extra cost item) he manages to
collect 8000 10 bit analog samples and perform 2000 arc tangent
calculations in 250 milliseconds. The arc tangent calculation method
is described in the article and employs straight line approximation
along with table lookup trigonometric functions to achieve the 6
microsecond speed mentioned. If you or your library don't have access
to Circuit Cellar you can order a back issue (print or download) or
download for purchase a single article for a few dollars from their
website www.circuitcellar.com

In fact, I don' t need a good precision, 1° is enough.
With a TI TMS320F2812 DSP at 150MHz I can do it in less than 1ľs with a
0.2° precision and a limited development method, but it' insufficient.

So with this development method, maybe I can do it with an FPGA and fast
ADCs.

Hope this helps, I'm curious to know the intended application of your
query.

It' a an industrial application with a high precision optical angle
encoder. We do image acquisition thanks to a photo multiplier with a
scan method.


Thanks.

David

 

[pes]

Fred Bartoli a ĂŠcrit :

Le Tue, 04 Sep 2007 03:22:22 +0100, Eeyore a ĂŠcrit:

pes wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns : (Acquisition of the ADCs,
ArcTang operation and genereate the interrupt). What performance can I
hope ?

What about the MicroMega UM-FPU V3.1 ?
In 100ns !!! ?

Just the time taken alone to transfer the data in and out via the
SPI/I2C interface will take many microseconds.


Uh?

100ns is just 10MHz. These days it's POC.
For ex. AD has the AD9254 and AD9640-150 which are resp. a single and a
dual 150MHz 14b ADC. They also have three 16b >100MSPS ADCs.
They have fifteen 14b ADCs and eight 16b ADCs that fit the > 10MSPS
criteria.
Just stuff the output stream to a small FPGA, let it manage the other
functions too and it's done. Not a big deal really.

Yes, but I will have preferred a little component because I don' t have
experience in FPGA and I think it will complicate the design.

The only possible question is the arctan latency. But even 16b accuracy
isn't much at all and a simple table driven + interpolation algorithm
will easily take care of that. Or even a simple dumb 64K size table.

Ok, the solution is sufficient I think.

But...
but the OP didn't tell what the ADC resolution has to be, and so on...
This and a lot of details seem to indicate that he's just throwing some
ideas without any understanding of what he's doing and what he really
needs.

Not needed a big reolution.
The final 1° angle resolution is enough. So regards to the electronic an
12b ADC seems to be appropriate.

 

[Eeyore]

pes wrote:

Eeyore a écrit :
pes wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?

In 100ns !!! ?

Just the time taken alone to transfer the data in and out via the SPI/I2C
interface will take many microseconds.

Hi, the serial bus in only intended to setting parameters of the time
which the interrupt will be released according to the angle calculated.

How exactly do you think the data that needs to be converted gets into the
co-processor (and how does the result get outputted) ?

Graham

 

[pes]

Eeyore a écrit :

pes wrote:

Eeyore a écrit :
pes wrote:

Hi all,

I' m looking for a co processor which have two ADC inputs ,an output to
generate an interruption and an indifferent serial bus to communicate.

I would like to do this operation in 100ns :
(Acquisition of the ADCs, ArcTang operation and genereate the interrupt).
What performance can I hope ?

What about the MicroMega UM-FPU V3.1 ?
In 100ns !!! ?

Just the time taken alone to transfer the data in and out via the SPI/I2C
interface will take many microseconds.
Hi, the serial bus in only intended to setting parameters of the time
which the interrupt will be released according to the angle calculated.

How exactly do you think the data that needs to be converted gets into the
co-processor (and how does the result get outputted) ?

The data will get into the co-processor by ADC(s), and when compare to
the angle parameter will generate an output on a GPIO.
I have seen that the Micromega UM-FPU V3.1 have this peripherals. I
haven' t the ADC coversion time of this component but I suppose it will
be longer that I needed.

Graham