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RE: PCMCIA interface or CompactFlash or general I/O



Hi!

CF defines two different operation modes:

1. IDE compatible mode. Used by memory devices e.g. flash 
cards for digital cameras. For this type of card it should
be possible to use the IDE interface on the ETRAX (It has 
been done).
2. PCMCIA compatible mode. This is used by e.g. 802.11
cards. PCMCIA can be implemented in a number of ways:
   2a. On general I/O. Has been verified to work. One of 
       our customers has a website for such a product, 
       http://rnd.balt.net. Last time I checked the PCMCIA
       driver source was downloadable from the site. The
       drawback with this soultion is that ETRAX will be
       occupied doing polled I/O instead of more 
       interresting tasks.
   2b. FPGA. This solution is used in the AXIS 5900 wireless
       printserver. No linux driver is available available 
       (The 5900 doesn't use Linux so the GPL is not
       applicable). I am not sure if we would give you the 
       FPGA source.
   2c. Directly on the system bus. Should work in theory 
       with a few external gates. Slow cards can cause
       Ethernet overruns or underruns (because the card
       issues a long wait request to ETRAX which prevents
       the DMA from accessing memory. Has never been tested
       in practice with ETRAX but works fine with other 
       processors with a similar bus interface.

Good luck!       

Best Regards
/Mikael