CompactFlash driver

Hey guys,

I am currently trying to develop a C-driver for a CompactFlash device. I am driving the CF device in Memory mapped mode, 16bit transfer enabled. However, I am observing some very strange behaviour, which is not caused by a malfunctioning card (I checked with a card reader, the card is fine).

The problems I have observed are as follows:

- Writing to Sector Count register, followed by a write to the Sector Number register, will end up overwriting the value in the Sector Count register with a completely random value. If I change the order of the writes, then Sector Number will get overwritten, again with a very random value. The same occurs for the Cylinder Low and Cylinder High registers.

- Writing ANY value (with DRV=0) into the Drive/Head register, irregardless of whether LBA is set or not, will cause the Error bit in the Status register to become set!

- Writing a command into the command register will overwrite whatever value I have in the Drive/Head register: typically HS0 - HS3 get set, LBA, D5 and D7 get all cleared.

Because of the above "phenomena", I find it impossible to write or read sectors from the card. I was hoping that you could point me towards some area where the problem could lie, such as wrong start-up routine (I Reset the card, disable interrupts in the Device Control Register, set the card as drive 0) or possible signalling problems (although the signals that I observed via a signal analyser seemed to be just fine?)

I really have no idea why the card would behave as randomly as this, and I would appreciate any help you could provide me with.

Thanks a lot in advance.

I also need some information about this driver... if anybody have any info about this please help me

Thanks in advance
Eaby