external ram addressing ( CompactFlash) with AT89C51SND1

Hi,

I try to communicate with an compactflash with external memory (movex). My microcontroler is AT89C51SND1

My initial values :

extern  xdata Byte volatile CF_SECTOR_COUNT _at_ 0x1F2;

 // this address is that the good address?
             // I find it in  site http://www.compactflash.org
             // Specification Revision 2.0

CS0 = 0x00;

 //CS0

CS1 = 0x01;

 //CS1

PIO_RESET = 0x01;

AUXR = 0x0D;

 //is that true in write and read
               // cycle and about ALE ?

CF_SECTOR_COUNT = 16;

 //for example

printf("CF_SECTOR_COUNT=%x \n\r",CF_SECTOR_COUNT);

AUXR=0x0D;

Is that the good way to write and read on registers of external periphericals ?
For addresses must I add the at first external ram address of my microcontroller (0800h) the address of CF registers 0x1F2 ?

Thank you

Sems