cyliax@ecn.purdue.edu (Ingo Cyliax) (06/07/91)
Has anyone tried the above combination ? What are some of your experiences ? Gotchas ? Thanks, -ingo -- /* Ingo Cyliax ECN, Electrical Engineering Bldg. * * cyliax@ecn.purdue.edu Purdue University, W. Lafayette,IN 47907 * * cyliax@pur-ee.UUCP Work: (317) 494-9523 * * cyliax@flaubert.laf.in.US Home: (317) 742-4173 */
rjs@alice.att.com (Bob Safranek) (06/11/91)
I was asked to post the following by colleague of mine...
Bob Safranek
Signal Processing Research Dept.
AT&T Bell Labs
rjs@alice.att.com
I know of three errors in the current Ariel documentation. Since Ariel
are bound to change the documentation ("real soon now"), I note both
right way and wrong way:
1) ariel documentation incorrectly shows pin1 for SURFboard IO headers.
wrong: pin1 toward the inside of the board
right: pin1 toward the edge of the board
You'll fry the cable if you get it wrong, but probably won't damage
either SURFboard or Ariel (shorts VCC & GND).
2) ariel include 8574A chip for setting the sample rate. chip should
be 8574 (no "A" suffix). Entropic have a work-around, but our sample
programs won't work unless you modify the dcssr.c source. If (and
only if) you have a proportvme (ie Ariel) with an 8574A chip, change
the following line in dcssr.c from:
#define PCF8574 0x40
to
#define PCF8574 0x70
and recompile. The 8574(A) chip is near the pair of ribbon cable connectors
on the proportvme.
I don't know the magic Entropic workaround, I think it's an undocumented
switch. Check with Entropic. You can also buy an 8574 from a distributor,
e.g. Hamilton/Avnet or Arrow, it's about $5, maybe less. Mfr is Signetics
(or Philips, which owns Signetics), part number PCF8574P. Or you can ask
Ariel to give you the right chip. They're good people, and will probably
oblige, but of course I can't make a commitment for them.
3) Ariel dox show proportvme attached to the wrong dsp cluster.
wrong: proportvme across from VME connector P1
right: proportvme across from VME connector P2.
If you don't know VME connectors, hold the board in front of you with
the two 96 pin connectors at the right, chips facing you, dsps will be
at top and bottom left, more or less. P1 is the 96 pin connector at top
right, P2 is 96 pin connector at bottom right. Entropic software assumes
you have proportvme attached to the dsp cluster at bottom left.
Originally, AT&T ME planned to co-market SURFboard and Ariel ProPortVME,
but AT&T ME (unilaterally) changed their plans, and there's been little
communication between the two on this subject since. AT&T ME plans to
license SURFboard to an outside VME house within the next few months,
and I am told that the VME house would like to support proportvme as
well, so at some point ("soon") it should all come together.
As the designer of SURFboard, I would be interested in hearing any (very
specific) positive or negative experiences anyone has had vis-a-vis SURF-
board and SURFboard support. I am not associated with the organization
responsible for selling SURFboard, nor am I associated with product support,
but I will forward any comments to the appropriate individuals. (No promises
above and beyond, express or implied.)
Jim Snyder
AT&T Bell Labs
Signal Processing
Research Dept.
jhs@research.att.com