On Tue, 22 Apr 2008 08:24:27 +0200, Denkedran Joe wrote:

> Hi,
> 
> I'm using a Xilinx Virtex-II Pro FPGA on a self-designed PCB and I'd
> like to ask for a way to program the embedded PowerPC independently from
> booting the whole FPGA via the Xilinx Platform Flash. Is there a way to
> account for that, maybe be designing an additional Flash device in the
> BS chain? Is it even possible to run the PowerPC even though the FPGA is
> not programmed?
> 
> Regards
> Joe

The processor pretty much has to run out of memory blocks in the FPGA, 
that happen to be initialized to a particular pattern from the flash, 
right?  So find a way to load up your program into the pertinent memory!  
There's a gazillion different ways to do this, depending on what you're 
trying to do.  Here's some:

* Use an itty bitty serial download program that accepts Motorola hex 
files
* Use an external parallel-access flash part and run straight out of that 
(this is slow, and uses lots of pins, but it's easy).
* Use an extra serial flash device that's _not_ in the BS chain, that you 
can bit-bang from the processor to load memory.
* Use an external NAND flash part (with lots of on-board memory to read 
it).

IIRC the PowerPC core floats in the Xilinx part until you connect it - 
there's no dedicated pins to get to the outside world.  So you're out of 
luck until you program the FPGA.  I think the Atmel FPSlic parts 
connected the processor straight to the outside world, but they're not 
nearly as powerful, and they were kind of a flash in the pan -- I don't 
know how they're doing or how well they're supported now.

-- 
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

Denkedran Joe wrote:
> Hi,
> 
> I'm using a Xilinx Virtex-II Pro FPGA on a self-designed PCB and I'd like to 
> ask for a way to program the embedded PowerPC independently from booting the 
> whole FPGA via the Xilinx Platform Flash. Is there a way to account for 
> that, maybe be designing an additional Flash device in the BS chain? Is it 
> even possible to run the PowerPC even though the FPGA is not programmed?
> 
> Regards
> Joe 
> 
> 

I'm curious.

Assuming that you could run a program on the Virtex-II Pro PowerPC using 
data stored in caches, but not connected to anything else in the device 
as you haven't programmed a design into the FPGA what exactly would you 
do with it?

Ed McGettigan
--
Xilinx Inc

No, becuase you need to program the FPGA to at least form the memory and 
bus(es) for the processor to work.  You don'y have to use flash, you can 
program an FPGA many ways.  Xilinx has a document covering configuration 
options.


---Matthew Hicks


> Hi,
> 
> I'm using a Xilinx Virtex-II Pro FPGA on a self-designed PCB and I'd
> like to ask for a way to program the embedded PowerPC independently
> from booting the whole FPGA via the Xilinx Platform Flash. Is there a
> way to account for that, maybe be designing an additional Flash device
> in the BS chain? Is it even possible to run the PowerPC even though
> the FPGA is not programmed?
> 
> Regards
> Joe

Hi,

I'm using a Xilinx Virtex-II Pro FPGA on a self-designed PCB and I'd like to 
ask for a way to program the embedded PowerPC independently from booting the 
whole FPGA via the Xilinx Platform Flash. Is there a way to account for 
that, maybe be designing an additional Flash device in the BS chain? Is it 
even possible to run the PowerPC even though the FPGA is not programmed?

Regards
Joe