Prop II Information?

AndrewP

Where can I find more information on the Propeller II?· I've looked through the site and all I've found so far is the press release for its demonstration.· I use the Propeller chip·in a commercial video product and have been experiencing severe instabilities at high resolution, 1280x1024.· It looks like the Prop II may be a better solution for my needs, but I can't find any other info besides·some·commentary on the forums.

Mike Green

The commentary on the forums is all there is. The Prop II is under development. There are no projections of when it will be available or exactly what its features will be. It's pretty well established that it will have 256K of hub memory and probably 8 cogs, each with pretty much the same instruction set as the current Prop I with some new instructions added. It will have 16 x 16 multiplication. It will be a lot faster with an expected 160MHz clock and pipelining to provide one instruction per clock cycle. Internally, it will operate on 1.8V and I/O will be 3.3V. For further information, you can read the forum discussion and there are summaries in 3rd party websites.

It is likely that any instabilities you're experiencing are due to something about your design or implementation. There are VGA drivers available with resolutions up to 1600 x 1200 and my experience is that they're rock-solid. The higher resolutions tend to use pretty much all of the resources available (cogs & memory), but whatever cogs and memory are left are unaffected by what's going on in the display cogs. That's one of the beauties of the Propeller's design.

AndrewP

Thanks for the info. I produce the same instabilities using the demonstration driver and have produced some of the problems on the proto board. I didn't write the production code but my programmer says Parallax gives it the OK. There are no issues at lower resolutions. It's a very simple product almost identical to the demo circuit. The chip is still running and reading data, but hsync pulses "split" and lose timing. The only conclusion I've been left with is we're pushing the limits of the Prop because problems are intermittent and unpredictable. I've been dealing with the problem for over a year with little progress so hopefully the Prop II will be a solution when availabe.

Roy Eltham

There is a page on the wiki that attempts to summerize the "planned" features for the Prop II, and it has links to the main threads here discussing it.
I've just updated it recently, and will be doing more updates as time permits.

The link is in my sig below.

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Check out the Propeller Wiki·and contribute if you can.

Mike Green

AndrewP,
Given that you've reproduced the problem with one of the demo programs, I strongly suggest you post a more detailed description of the instabilities complete with attachments for your copy of the demo program and a schematic of the board since it's so close to the Demo Board in design. The Propeller was specifically designed to avoid instabilities by making everything deterministic and using an inherently robust design. The high resolution video drivers make use of some programming "tricks" to get the high data rates involved by syncing several cogs so that one is sending a group of scan lines while the others are building the next set of scan lines. This should all still be deterministic. Maybe there's a bug in the driver code. It's very unlikely that there's a problem in the Propeller itself, but your problem needs to be explained and that requires that it be reproducible by others.

Sapieha

Hi AndrewP

Look at this thread.....
Is it same behavior....?
http://forums.parallax.com/forums/default.aspx?f=25&m=215415

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Nothing is impossible, there are only different degrees of difficulty.
For every stupid question there is at least one intelligent answer.
Don't guess - ask instead.
If you don't ask you wont know.
If your gonna construct something, make it·as simple as·possible yet as versatile as posible.


Sapieha

AndrewP

Looks similar but not the same.

If it becomes appropriate I'll start a separate thread about the issue we're having. Thanks for the further info on the Prop II.

Sapieha

Hi AndrewP

What frequency You run on crystal.

Ps. If You run 5MHz crystal x16. You can test with 10MHz crystal and x8. It is possible at that configuration works perfectly.

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Nothing is impossible, there are only different degrees of difficulty.
For every stupid question there is at least one intelligent answer.
Don't guess - ask instead.
If you don't ask you wont know.
If your gonna construct something, make it·as simple as·possible yet as versatile as posible.


Sapieha

Post Edited (Sapieha) : 9/22/2008 7:33:41 PM GMT

william chan

No more 16 cogs?

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www.fd.com.my
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Rayman

I would guess that the instabilities he refers to are due to the use of multiple "synced" cogs to generate the video. I think there is some sub-pixel timing offsets between cogs...

hippy

william chan said...
No more 16 cogs?

It seeme to be looking that way. More information on that here ...

http://forums.parallax.com/showthread.php?p=746473

cgracey

Rayman said...
I would guess that the instabilities he refers to are due to the use of multiple "synced" cogs to generate the video. I think there is some sub-pixel timing offsets between cogs...

It's true that there will be some sub-pixel offsets between the cogs for higher-res drivers. This can't really be helped. However, some LCD monitors have better PLL's than others. If you get a good make/model, there should be no pixel-edge noise. Another thing that is very important is to have good =>1uF ceramic bypass caps right near the Propeller's power pins.

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Chip Gracey
Parallax, Inc.

Timothy D. Swieter

Note the plural fom - CAPS. I had a design with two caps in it. Recently it was changed to four+ and that helped with a couple noise issues. At the Propeller Expo I got a chance to talk with Paul Baker. He reminded me of the EDN article and thread on this forum about caps on the Propeller power supply. I believe there was a mention of 6 to 8 caps for really trying to reduce noise and power related problems.

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Timothy D. Swieter, E.I.

www.brilldea.com·- Prop Blade, LED Painter, RGB LEDs, uOLED-IOC, eProto fo SunSPOT, BitScope
www.sxmicro.com - a blog·exploring the SX micro
www.tdswieter.com

Paul Baker

I actually have the board AndrewP has been experiencing problems with, his programmer and I have been in communication. I will be trying to diagnose it shortly.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.