Re: Yosemite/440EP 'issues' as a PCI target

Dear David,

in message [off-list ref] you wrote:

Of course there is also the option of finding another
PowerPC that matches my requirements;

...

MPC834x comes to mind. But I have to admit that we never tried  using
this as a PCI device yet...

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
I can type faster than I can move a  mouse,  so  I  find  menu-driven
drawing packages time consuming and frustrating.      - W. R. Stevens

quoted

Of course there is also the option of finding another
PowerPC that matches my requirements;

...

MPC834x comes to mind. But I have to admit that we never tried  using
this as a PCI device yet...

Thanks Wolfgang, I'll take a look at the user manual.

Regarding PowerPC devices that can be (uselessly) configured
as PCI agents/targets/peripherals;

  - the Artesyn PMC board I got from eBay contains the
    IBM CPC700 bridge - it can never generate PCI interrupts
    as a target (non-monarch mode).

  - the MPC5200 PowerPC, can also be configured as a target,
    but will never generate PCI interrupts.

Gee, who knew. I didn't :)

Dave

Hey Travis,

 >> Not great, so any suggestions for whats better?
 >>
 > Everyone uses them because they're easy and just work. Sometimes
 > you may need to tweak the setup eeprom, but in general they just work.
 > We use a pericom 7300 (can't remember and working from home
 > today), that is quite nice.  Not an issue with it at all. HW
 > guy just plunked it down and it worked.  They have an eval board to.

I was going to take a look around TIs site, I'd forgotten Pericom
makes bridges too, I'll read the data book.

 > ... I've not had a need to use it, my work is 90% PCI
 > (forwarding engine, queueing engine, etc) for 10G ethernet, so
 > FPU stuff is very rare, and not time critical (used for setting
 > up policing/rate limiting etc). Basically, set it and forget it
 > calculations.

I figured that was probably the case - and the reason the majority
of the embedded processors are sans-FPU. I didn't want to use a
TI DSP again, there's just no 'community spirit' like with Linux.

So, I'll take a look at the PowerQUICC that Wolfgang mentioned, and
see if I want to change to that processor, another look at the ColdFire
(I have an MCF5485 eval board), and a look at the bridge data sheets
and see where that leaves me.

Personally, I want to stay with the PowerPC, the developer mailing
list is great!

Thanks,
Dave

Hi Wolfgang,

quoted

Of course there is also the option of finding another
PowerPC that matches my requirements;

...
MPC834x comes to mind. But I have to admit that we never tried  using
this as a PCI device yet...

Indeed you were correct. The MPC834x series meets my requirements.
It is also a 3.3V PCI device, so I'm checking into whether
the Trenton CPUs I can use as host CPUs use a 3.3V PCI interface.
If that is the case, then I'll move the Force CPUs into another
system, and I'll just define the cPCI bus in the correlator
system as 3.3V-only.

The potential advantages of the MPC834x over the 440EP are;

   - it has doorbell registers and mailboxes for PCI
     host-to-host comms (though does not have an I2O interface)

   - its DDR-SDRAM controller can run faster than the 440EP

   - its external local bus is wider and faster than
     the 440EP

   - but I think the MPC834x internal buses are slower than
     the 440EP CoreConnect buses, so I'll need to benchmark
     to compare the two.

   - it exists! I can find them on distributors web sites
     (can't say the same for the 440EP yet!)

So, I'll continue with my evalation of the 440EP, and then
I'll want to evaluate the MPC834x devices.

What MPC834x development kit are you using? What would you recommend?

  - I'd like to get a board in a PCI or cPCI-form factor, since
    I could use it as a PCI agent/peripheral
  - I'd really like to get access to the external bus
    too.

Embedded Planet has a PrPMC module with an 8343E, but I doubt
I can get to the local bus on that board. I found news releases
of an MPC8349E QUICCstart board, but couldn't find anything
on Freescale's web site. Wind River appears to have an eval
board; SBC8347E/49E, which looks to be a cPCI board, but their
web site didn't have much in the way of details (or pictures).

Freescale do have the MPC8349EMDS 'MPC8349E Modular Development
System', but its not clear how much of that system I would
need to purchase just to test the board in a PCI system.
Looks like its aimed toward AdvancedTCA development.

Anyway, thanks for the pointer to the MPC834x series!

Dave

Hi David,

On Saturday 11 February 2006 07:03, David Hawkins wrote:

Indeed you were correct. The MPC834x series meets my requirements.
It is also a 3.3V PCI device, so I'm checking into whether
the Trenton CPUs I can use as host CPUs use a 3.3V PCI interface.
If that is the case, then I'll move the Force CPUs into another
system, and I'll just define the cPCI bus in the correlator
system as 3.3V-only.

Ahhh. ;-)

The potential advantages of the MPC834x over the 440EP are;

   - it has doorbell registers and mailboxes for PCI
     host-to-host comms (though does not have an I2O interface)

   - its DDR-SDRAM controller can run faster than the 440EP

   - its external local bus is wider and faster than
     the 440EP

   - but I think the MPC834x internal buses are slower than
     the 440EP CoreConnect buses, so I'll need to benchmark
     to compare the two.

   - it exists! I can find them on distributors web sites
     (can't say the same for the 440EP yet!)

Hmmm. The 440EP is around for quite a while. I would be surprised if you 
couldn't buy those parts right now. But I have to admit, I never tried to. I 
would contact my AMCC distributor for availability...

Best regards,
Stefan

Hmmm. The 440EP is around for quite a while. I would be surprised if you 
couldn't buy those parts right now. But I have to admit, I never tried to. I 
would contact my AMCC distributor for availability...

I always figure that if you can find it on a distributor web
site without having to explicitly ask for the part, then
it really is available. I got my Yosemite kit through
Avnet, so lets start there:

1. Avnet

    http://www.em.avnet.com

    Search for 440EP from the vendor AMCC, and it only shows up
    the eval boards.

    Search for 'contains' MPC834 from Freescale, and there are
    lots of hits (though no stock for most of them).

2. Arrow North America

    http://www.arrownac.com

    No AMCC stuff there.

    A search for the Freescale part shows up a bunch, although they
    have no stock either.

The successful search hits for the Freescale part gives me
more confidence in those parts. However, you are correct, if I
really want to know the availablity of parts, I should talk
directly to an AMCC rep.

Cheers
Dave