We are trying to use an RS232 CF card on our custom board, but the device does not generate any interrupts. Are there any reference schematics for the CF and AT91RM9200 that have been proven to work? We have no problems using 802.11 and memory CF cards.

Hello David,

I was not aware of this kind of CF cards,
How it is connected to the RM9200 ?

Bye,

Patrick

We've connected the CF port very much like the schematics for the DK board. We've also added /IOIS16 to PB2 and /STSCHG to PB3. I think these are the only differences.

Are you aware of this FAQ about CF card on the DK ?

http://www.at91.com/Pages/faq/69.html

Bye

Yes, I am aware of this faq. We did not lay out our board this way.
After more checking I found out that we can access a 64M CF memory card in I/O mode, but we have problems in memory mode. I can not access a 128M CF memory card in either mode.
An 802.11 CF card works in I/O mode, but it doesn't work in memory mode.

dapper

I am using a custom board with CF interface almost identical to -DK schematics. Not far off your additions.

We operate CF card in 16 bit memory mode without problems. Up to 2Gig at moment.

The main modfications to the sample code were in loop timings. (Running with I- and D-cache the while ..cpt++ < 1000 was way too short.). I also added write multiple and read multiple routines.

The main bug I found (and it took a long time to find) was my power supply drooped when doing a lot of CF writing and corrupted the data. Some cards really sap the 3.3 volt supply.

Hope this helps find your problem.

Simon

I changed some of the timeouts and now have the memory cards working in both I/O and memory mode. The RS232 cards still do not work.

Hi Guys,

Dapper what do you mean by "We did not lay out our board this way." do you mean the DK's way without taking into account the FAQ or ?

Simon, same question for you what do you mean by "CF interface almost identical to -DK schematics" ?

Thanks Simon and Dapper.

Regards,

We are not using CFOE to control data direction as the DK is. We are using CFRNW to control the data direction for the data bus. CFOE is tied to the CF port through a buffer ic.
Like I said previously, memory cards work great, but rs232 cards don't. Are there any control lines that an rs232 cf card would use that the memory cards don't?

We have our board layed out very much like page 145 (Figure 35. CompactFlash Application Example) in the AT91RM9200 datasheet.

pfillipi

We use different buffer chips on data lines. We drive the address bus through single direction buffers to reduce BOM price.

CD1 and CD2 circuit different for our own reasons. We also drive the CE2 and CE1 lines through spare gates on some other logic chips we have on the board.

We need to be able to "hot" insert remove and detect CF card and found a few "glitchs" with the DK. So there is a little more pull downs and power supply filtering.

Other than that the -DK was an excellent starting point.

Simon

The more that I look at this the more I think there is a driver problem. We are running Linux 2.4.27-vrs1. I've gone through some of the code and everything appears to be getting set up properly, so I'm not sure what else to check.

dapper

Do you mean hardware drivers or Linux drivers ?

If you mean the first, my bet would be power supply. The second no idea, not my department.

Good luck and when you find the solution let us know, we may be there in the months to come.

Simon