xintf zone6 question

hi all,

i have ezdsp f28335,so i want to use xintf zone 6 for my external memory. my C-code is:

in linker comand file

MEMORY
{
    .....
    PAGE 1 :
       ZONE6      : origin = 0x100000, length = 0x000003     /*XINTF zone 6 - data space 3x16*/

      ............
}
SECTIONS
{
    ........
       ZONE6DATA        : > ZONE6,       PAGE = 1
}     
In mainfile C-code:

#define     BUF_SIZE   3  // Sample buffer size for 3 duty cycle

#pragma    DATA_SECTION(Buf , "ZONE6DATA" );

volatile   Uint16    Buf[BUF_SIZE];       // i dont know whether i must use keyword "volatile" or not ?
.........
//so in ISR(interrupt service routine) :
........
 intterupt  void  main_isr(void)
{
    ...........
    ...........
    BUF[0] = (Uint16)(....);
    BUF[1] = (Uint16)(....);
    BUF[2] = (Uint16)(....);
    ..........
}
 
question is : is it right???
  For the first assignment  BUF[0], so addressline  A1 = 0 and A0 = 0,   WE = 0, CS = 0
  For the 2nd assignment  BUF[1], so addressline  A1 = 0 and A0 = 1,  WE = 0, CS = 0
  For the third assignment  BUF[2], so addressline  A1 = 1 and A0 = 0,  WE = 0, CS = 0

many thanks!

tequila