FPGA Central - World's 1st FPGA / CPLD Portal

FPGA Central

World's 1st FPGA Portal

 

Go Back   FPGA Groups > NewsGroup > FPGA

FPGA comp.arch.fpga newsgroup (usenet)

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 11-12-2007, 05:18 AM
m
Guest
 
Posts: n/a
Default Programming connection

Looking for ideas to eliminate the programming connector and replace
it with pads/contacts on the board. This is both for cost and size
reduction as well as simplifying programming during manufacturing and
testing.

One idea is to build a programming jig for each candidate board
containing a connector like this:

http://www.samtec.com/technical_spec...NDARD_PRODUCTS


Any ideas?

Thanks,

-Martin

Reply With Quote
  #2 (permalink)  
Old 11-12-2007, 05:22 AM
m
Guest
 
Posts: n/a
Default Re: Programming connection

Here's another option:

http://www.yokowo.com/springpinconne...lications.html

-Martin


Reply With Quote
  #3 (permalink)  
Old 11-12-2007, 09:01 AM
Petter Gustad
Guest
 
Posts: n/a
Default Re: Programming connection

m <[email protected]> writes:

> Looking for ideas to eliminate the programming connector and replace
> it with pads/contacts on the board. This is both for cost and size
> reduction as well as simplifying programming during manufacturing and
> testing.


I've been looking into this too. I want to add a 1x PCI-Express edge
connector on my board for programming. Programming and JTAG testing
will be done by inserting the board into a PCI-Express 1x slot on my
test bench. Anybody else doing this?

Petter
--
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?
Reply With Quote
  #4 (permalink)  
Old 11-12-2007, 02:03 PM
Nial Stewart
Guest
 
Posts: n/a
Default Re: Programming connection

> I've been looking into this too. I want to add a 1x PCI-Express edge
> connector on my board for programming. Programming and JTAG testing
> will be done by inserting the board into a PCI-Express 1x slot on my
> test bench. Anybody else doing this?



I've thought of something similar, but probably with a 'bed of few nails'
rather than an edge connector.

If you standardised in a 'footprint' of pads on the bottom of the board
you could use a standard test rig with moveable top/edge locating
strips.

The problem with the edge connector is that you're left with a protruding
connector on your PCB.



Nial



Reply With Quote
  #5 (permalink)  
Old 11-12-2007, 03:34 PM
Petter Gustad
Guest
 
Posts: n/a
Default Re: Programming connection

"Nial Stewart" <nial*REMOVE_THIS*@nialstewartdevelopments.co.uk >
writes:

> The problem with the edge connector is that you're left with a
> protruding connector on your PCB.


In my application this is not a problem. I've worked on PCI and PCIe
designs, but I have never seen the cost of actually cutting the edge
connector.

Petter
--
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the
most annoying thing on usenet and in e-mail?
Reply With Quote
  #6 (permalink)  
Old 11-12-2007, 03:48 PM
m
Guest
 
Posts: n/a
Default Re: Programming connection

> I want to add a 1x PCI-Express edge
> connector on my board for programming.


I thought of various edge connector ideas. For some reason I don't
like it, although it could be the most sensible.

Here's another thought, take a SOIC 8 test clip, like these:

http://www.pomonaelectronics.com/pdf..._5437_1_01.pdf

and trim the plastic such that the pins that would normally contact
the IC can go through holes in the PCB. One could lay out a very
compact (narrower than 0.15in SOIC) hole pattern that the clip could
go into. If you only need four pins you could place the holes near to
the PCB edge and have only one side of the clip engage the holes while
the other side simply clamps against the outer edge of the PCB (the
holes being about 0.1in from the edge).

In fact, in the four contact case I would probably opt for an 8 pin
DIP clip simply because of it being a lot more rugged.

No decision yet, just going through various permutations and ideas
now.

-Martin

Reply With Quote
  #7 (permalink)  
Old 11-12-2007, 05:32 PM
John_H
Guest
 
Posts: n/a
Default Re: Programming connection

"m" <[email protected]> wrote in message
news:[email protected] oups.com...
> Looking for ideas to eliminate the programming connector and replace
> it with pads/contacts on the board. This is both for cost and size
> reduction as well as simplifying programming during manufacturing and
> testing.
>
> One idea is to build a programming jig for each candidate board
> containing a connector like this:
>
> http://www.samtec.com/technical_spec...NDARD_PRODUCTS
>
>
> Any ideas?
>
> Thanks,
>
> -Martin



You can look at a closeup of a spring-pin connector on page 6 of the
DesignCon 2005 paper

http://www.coe.montana.edu/ee/lamere...vantages_1.pdf

Precision Interconnect appears to be the folks that worked with Agilent to
get the "soft touch" Logic Analyzer probe up and running.

http://www.precisionint.com/HighSpeedData/SpringPin/

Another paper I saw suggests the spring pins are good for "up to 500"
contact cycles though spring pins in general can have much better mating
life, so please double-check the suggested mating cycles in any of your
solutions.


Because you're so concerned about cost, I'll assume you have a very high
production. I'd suggest just going straight to a good spring-pin source and
making your own probe block. By using the appropriate crown or point style
of pin, you can avoid the added expense of gold-plating your board as may be
needed for many of the rounded-tip spring pins. The pins are available with
replaceable contact points so you can have your pre-assembled contact block
with fixed receptacles and just replace the individual spring-loaded points
as they wear.

These "pogo pins" are available from many sources but Interconnect Devices -
www.idinet.com - is the source that I've seen in ATE for decades. These
pins are available through distribution as well so getting them shouldn't be
a problem.

It is a shame there isn't a market of simple connector headers like this
pre-made, providing a simple ribbon cable connection. I've wanted contacts
like these for all those unpopulated programming connectors on production
(or near production) boards. Since my own needs are just the occasion board
trouble-shoot rather than programming, I've considered putting something
very rough together at various times but never managed to make it happen.

If you want some custom stuff done for you and you're willing to go for the
expense now for the savings in hassle and cost later, places like
http://www.ironwoodelectronics.com do custom work and have experience with
the pogo pins and the mechanics needed for a robust solution.

Good luck,
- John_H


Reply With Quote
  #8 (permalink)  
Old 11-12-2007, 08:30 PM
m
Guest
 
Posts: n/a
Default Re: Programming connection

> Because you're so concerned about cost, I'll assume you have a very high
> production.


While I am not high production, the extra cost becomes significant for
some assemblies. If we get away from FPGA's and enter into the world
of small inexpensive microcontrollers in equally small boards, adding
a programming connector is expensive in more than one way. Typical
connectors used for JTAG programming can dwarf microcontrollers and
expand the PCB. There's also the wear-and-tear on the programmer side
of the ribbon cable if you are doing a few hundred boards at a time.

I guess I am looking for a solution that we can adopt across new
designs and keep life simple. Although the financial cost of
connectors might not be all that significant, there's a lot more
beyond raw cost that makes them undesirable.

Thanks for the link to the paper describing the "soft touch" test
connector. It sounds like a very good solution for test and
troubleshooting needs.

-M

Reply With Quote
  #9 (permalink)  
Old 11-12-2007, 10:19 PM
Gabor
Guest
 
Posts: n/a
Default Re: Programming connection

On Nov 12, 3:30 pm, m <[email protected]> wrote:
> > Because you're so concerned about cost, I'll assume you have a very high
> > production.

>
> While I am not high production, the extra cost becomes significant for
> some assemblies. If we get away from FPGA's and enter into the world
> of small inexpensive microcontrollers in equally small boards, adding
> a programming connector is expensive in more than one way. Typical
> connectors used for JTAG programming can dwarf microcontrollers and
> expand the PCB. There's also the wear-and-tear on the programmer side
> of the ribbon cable if you are doing a few hundred boards at a time.
>
> I guess I am looking for a solution that we can adopt across new
> designs and keep life simple. Although the financial cost of
> connectors might not be all that significant, there's a lot more
> beyond raw cost that makes them undesirable.
>
> Thanks for the link to the paper describing the "soft touch" test
> connector. It sounds like a very good solution for test and
> troubleshooting needs.
>
> -M



Also don't assume that gold plating increases the board cost
significantly.
We've been using ENIG (electroless nickel/immersion gold) on all of
our
production boards for some time now. We initially changed to ENIG due
to process problems with white tin, but stuck with it when we realised
that the cost differential was small. This is not the same sort of
plating you would need on an edge connector finger. Connectors need
at least 15 microinches of gold plate to be reliable. The ENIG
plating is very thin, but enough to increase the board's shelf life
if you don't build them up right away. And the "pogo" style pins are
non-wiping so you should still get several programming cycles out
of the ENIG's minimal plating.

Regards,
Gabor

Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Current programming hardware does not support Active Serial programming mode Nevo FPGA 0 12-09-2006 05:46 PM
Connection between FSL and XCL Marco T. FPGA 1 01-29-2006 10:41 PM
Any advice on programming XSA-50 w/ programming header pins cargopatch FPGA 0 08-02-2004 11:07 PM
Altera Cyclone Programming device programming Rene Tschaggelar FPGA 3 01-17-2004 01:43 AM


All times are GMT +1. The time now is 04:04 AM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.2.0
Copyright 2008 @ FPGA Central. All rights reserved