Rene Tschaggelar wrote:

>> Just courious, when you're faced with new embedded design, what
>> criteria that you use to select the design base (FPGA/CPLD based or
>> microcontroller/microprocessor based)?

As with anything...
* Cost (development, manufacture/unit)
* Time (development effort)

FPGA's are useful for logic that is too proprietory/complex to use COTS 
parts, or high-speed logic that just won't cut it in software. Or 
perhaps there are several functions that would require a selection of 
COTS parts but would fit nicely into a single FPGA. Or perhaps 
real-estate is critical.

>> What projects is good for FPGA/CPLD and what projects is good for
>> microprocessor/microcontroller ?

A few random thoughts...

If you're looking to glue a few small peripherals onto a small micro, 
then I'd suggest you go down the uC/uP path. It'll probably be cheaper 
and require much less development effort.

If you have some (more complex or high speed) logic that could benefit 
from a bit of software (to reduce development complexity) then perhaps 
an FPGA with embedded soft uC is the go.

Is there scope for the design to evolve - will an FPGA provide a 
platform that allows firmware-only upgrades to functionality?

Then you need to look at manufacturing - how does the FPGA compare with 
uC/uP solutions in terms of PCB requirements (layout, layers) and SMD 
technologies (eg. BGA)? Should it be servicable in the field? What's the 
lifetime of this product (can you still get the same FPGA in 10 years?). 
How much will the unit cost to make?

And there's always - want to learn something new and have some fun? ;)

Regards,
Mark

kunil wrote:

> Just courious, when you're faced with new embedded design, what
> criteria that you use to select the design base (FPGA/CPLD based or
> microcontroller/microprocessor based)?
> 
> What projects is good for FPGA/CPLD and what projects is good for
> microprocessor/microcontroller ?
> 
> Is there any good reference on this ?

Just as sidenote: There are also mixed systems.
Those how have a cpu and an FPGA/CPLD.
Yes, there are cpu cores for FPGA. Ever tried
those tools ? the compiler, debugger ?
I don't intend to put them down. I never tried
yet. I'd take me at least a month to have a closer
look.

As to the advantage of a mixed setup :
You have the cpu and the tools you're familiar with
plus you get a configurable digital hardware that
can do timing stuff, that the cpu cannot.

Rene
-- 
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

Just courious, when you're faced with new embedded design, what
criteria that you use to select the design base (FPGA/CPLD based or
microcontroller/microprocessor based)?

What projects is good for FPGA/CPLD and what projects is good for
microprocessor/microcontroller ?

Is there any good reference on this ?

Thank You