Re: Carte Blanche

[srkh28@gmail.com]

Maybe I should explain why this possible.

The FPGA on carte blanche is able to load its bit stream configuration
image from several sources. Carte blanche has two of these methods
implemented. The first is JTAG, with the highest priority, the second
is a generic SPI FLASH memory - an 8Mbit (1MB) FLASH device. If you
plug up a JTAG interface, the FPGA will always respond and accept data
over this interface, otherwise it will contact its dedicated SPI
interface and load a bit stream from there if its available.

Once the FPGA has booted, the dedicated SPI interface is relegated to
generic IO. This is where carte blanche can get its mits on the
interface and use the device for its own storage (the bit stream only
needs part of the device) which also allows us to reprogram the FLASH
with a new image if we wish to. On a power cycle, the FPGA once again
attempts to boot from SPI, and if a new image has been updated to
flash, it will load the new design into the FPGA.

Steve


 On Apr 3, 11:54 am, srk...@gmail.com wrote:
> Hi Michael,
>
> I thought you were discussing the development cycle. Sorry. But to
> reprogram carte blanche in say a closed running system is also
> possible - not totally on the fly though, a restart (power off/on) is
> required.
> If your happy to write the software that would be great. The steps for
> doing this are;
>
> 1. Choose a carte blanche image of choice from some sort of menu
> system from the running host
> 2. Contact Carte Blanche thru registers and download new image to card
> (where the registers could be located with existing card designs - ie
> 4MB memory board, is not resolved as yet)
> 3. Carte Blanche will take the new bit stream image from the apple II
> host and reprogram its SPI boot flash and respond back saying its
> complete
> 4. Restart (power cycle) your system and carte blanche will boot as
> the new card
>
> Of course, its possible to write a bad image to carte blanche that
> would send the board off into la-la land, meaning you would have to
> pop the top on your apple, plug up JTAG, and restore a known good
> image that way.
>
> Steve
>
> On Apr 3, 9:38 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
>
>
> > Alex Freed wrote:
> > > Michael J. Mahon wrote:
>
> > >> Steve, it wasn't immediately apparent whether it was possible to
> > >> re-program the board while it is installed by running Apple II software.
>
> > >> This would enable it to be a real "chameleon card", since configurations
> > >> could be loaded into the card in a few seconds to alter its personality.
>
> > > This ideas has been discussed on this forum but proved to be a huge
> > > task. More on the software side than the hardware side. Porting the
> > > JTAG programming tool to an 8 bit CPU with rather limited resources
> > > is far from trivial. And if you absolutely have to have it, you
> > > probably can. It's not too hard to make a Wiggler-style interface
> > > between an Apple parallel card and the JTAG port on Carte Blanche. Just
> > > write the software :)
>
> > I'd be glad to write the software if it comes to that.
>
> > But I'd rather access the card through its bus connection than by
> > using another (parallel) card.  Since an Apple parallel card is
> > little more than an 8-bit latch, that doesn't seem difficult.
>
> > I presume that the data formats and protocols for JTAG programming
> > are straightforward...  I'd expect what is essentially a "copy file
> > to port" operation, with some handshaking, initialization, and cleanup.
>
> > -michael
>
> > ******** Note new website URL ********
>
> > NadaNet and AppleCrate II for Apple II parallel computing!
> > Home page:  http://home.comcast.net/~mjmahon/
>
> > "The wastebasket is our most important design
> > tool--and it's seriously underused."- Hide quoted text -
>
> > - Show quoted text -- Hide quoted text -
>
> - Show quoted text -