Question on Xilinx VirtexProII PCMCIA support (FPGA boards).... please

I posted here before and got excellent responses, could you knowledgeable people also answer a simple questuion below? If you reply by email, REMOVE "SPAMNOMORE" in capital letters repeated in my address twice (edit address manually)!!

We need to make sure Xilinx VirtexProII FPGA boards have a PCMCIA interface (hardware) and software support, and whether inteface is a regular one usable with standard IEEE802.11 cards (WIRELESS LAN modules). The two boards (need info for BOTH!!) are: ML 300 and ML310 One is just a board another is a complete development kit, I am not sure yet.

I did contact Xilinx first, but here's what happened: At first Xilinx engineers said PCMCIA is not supported, but then came back to me saying this: ML300 board: the PCMCIA supported, whereas PCI is supported only with much more effort on our side. ML310 board: The opposite (i.e. the PCI is supported, while the PCMCIA is not fully supported.) Thus we're completely confused and need to double check these answers, before comitting time/money. I CAN"T CONTACT THEM ANYMORE FOR THE SAME QUESTION AS MY XILINX PERSONAL ID HAS ALREADY BEEN USED FOR THE SAME QUESTION, I'd appreciate if you help.

Mark Levitski wrote: : : We need to make sure Xilinx VirtexProII FPGA boards have a PCMCIA interface : (hardware) and software support, and whether inteface is a regular one : usable with standard IEEE802.11 cards (WIRELESS LAN modules).

Point one: Do you know the difference between PCMCIA, CardBus and PC-Card? This is essential, so stay with me here:

PCMCIA is just ISA plus autoconfiguration (No, not PnP) and slot spesific addressing. There are no WiFi 802.11 cards on PCMCIA bus that I know of, though there used to be some NE2000 based 10Base-TX PCMCIA cards out there. PCMCIA has its roots in som Japaneese SRAM card, but became PCMCIA in the IBM-PC based Laptop. For this reason it resembles the 16 bit ISA bus it was hosted on and derived from.

CardBus OTOH is just PCI plus hotswap capabilities in the same form factor that governs PCMCIA. This physical form factor with its 68 pin socket is known as PC-Card. All WiFi PC-Cards I know of utilize this 32 bit CardBus interface.

CardBus and PCMCIA bus can and do coexist on modern laptop sockets, but in general not on embedded targets. CardBus will in general be derived from a PCI host bus. I.e: No PCI 'above' the PC-Card socket, then no CardBus. And vice versa for PCMCIA. CardBus controllers for PC Laptops from eg. Texas Instruments contain a full PCI-to-ISA bridge to maintain backwards PCMCIA compatibility on the same PC-Card socket it offers CardBus on. Again, this is highly unlikely on embedded targets.

In addition, you have to know that CompactFlash is just a shrinked down PCMCIA bus. Just like IDE(ATA) is a shrinked down ISA bus. Compactflash looses some addressing capabilities and fit in a much smaller 50 pin socket but is in essence still an PCMCIA device.

The CompactFlash card has to present itself as an ATA disk by means of PCMCIA autoconfiguration. There is little to stop you from presenting anything else that might fit an PCMCIA bus on the CompactFlash interface during autoconfiguration. This is why you can get WiFi/Bluetooth/GPS/ whatever cards that fit the CompactFlash socket, even though hard to come by.

: The two boards (need info for BOTH!!) are: : ML 300 and ML310

As far as I am able to determine from a quick glance, both contain an so-called SystemACE that is connected directly to the FPGA and hence not hosted on the PCI bus. In addition, both ML300 and ML310 seems to sport an 50 pin _Compat Flash_ connector, not the full 68 pin PCMCIA connector. See explanation above.

But how about plugging an desktop PC style CardBus socket hosted on a PCI card into the ML310 PCI bus and attach your WiFi card into this? These PCI cards should be easy to come by. Or use a PCI based WiFi card.

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