How to independently program the embedded PowerPC in a Virtex?

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

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

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.