processor usage estimation (5282)

[dhan]

Hi,

I'm looking at using the 5282 but need an estimate of how much processing power I'll need. I'm new to embedded programming, so any help with getting some estimates in the ballpark would be appreciated. Here's an overview of what I want to run:

* OS + network stack
* Application state machine (~5-10 states)
* Message routing (to trigger state transitions and also for application messages in each state)
* Diagnostics and configuration for 2 cameras
* Control of a separate image processor. video will be piped over the ethernet.

Again, I'm just looking to get into the ballpark. e.g., whether this would take about 1/4, 1/2, 3/4 or the whole processing capability of the 5282.

Thanks!
Dave

[mjbcswitzerland]

Hi Dave

I don't think that anyone will be able to give you a figure based on your inputs.

You need to include the network loading, the message frequency, the state transition frequency, etc.

If the frequency is low it will use up about 0% of the processing power. If the load is high it may use up a lot of processing power - again depending on many other unknows.

It is not clear whether the images pass through the processor or not, what protocols are used and what DMA support is possible.

The operating system and stack software will make a difference so presently it is very speculative.

The network video cameras which you can buy for about $150 do about that what you describe and typically use an ARM9 and Embedded Linux. Maybe a comparison between the capabilities of ARM9 and the 5282 would make more sense for a first figure, but then I don't know the ARM9 loading taking place...it is however known to be suitable...

Best of luck.

Mark Butcher
www.mjbc.ch

[dhan]

Thanks Mark,

That's just the type of information that I need to know to get me headed the right direction. Here's some followup info to hopefully clarify my situation.

state transitions are infrequent. on the order of minutes.
message frequency is low also. It's limited by human interaction on one end, so lets say 10/sec.
we are hoping that the images do not need to pass through the processor. instead we are hoping that we can have the image processor package up the stream nicely and use the DMA attached to the ethernet component of the coldfire.

I'll take a look at the ARM9 specs and see what I can dig up about their loading.

Dave

[mjbcswitzerland]

Hi Dave

If that is the case then the processor seems to be very under-utilised. You could look at much cheaper variations for your project.

I have a Coldfire running OS and TCP/IP stack at the following address:
http://212.254.22.36
you can see it via web-cam at http://212.254.22.36:8080
It is running a web server, FTP server, Telnet, SMTP. Such applications represent practically zero load with may be a few short higher speed bursts, but nothing is real impact to such chips. There is also a MC9S12NE64 (a 16 bit freescale processor) doing similar stuff (also visible on the web cam) and contactable at http://212.254.22.36:8081 (User name "anon" password "anon"). Also this chip has no problems with loads experienced in such applications. I also use it for voice over IP where the load is constant and higher (mainly due to SPI interrupts when sending to and receiving from voice codecs) but it still represents only about a constant 15% loading (on the 16 bit chip).

Cheers

Mark
www.mjbc.ch

PS. If you need Ethernet check out also the new M5223X Coldfire chips since they have it onboard. See the following post for details.

http://forums.freescale.com/freescale/board/message?board.id=CFCOMM&message.id=274