How to access TMS570LS31 HDK SDRAM?

Hi,

I got TMS570LS31x Hercules Development Kit, and want to use the external 8MB SDRAM.
But, it seems that I can't access SDRAM.
Is there any initialization step to use SDRAM?

I made TMDX570LS31HDK project by HALCoGen(2.09.001) and "Generate Code" default settings.
I added some callback funcs and build projects CCS(4.2.5.00005).

In main func, I added the following codes to check access to SDRAM.

  volatile int *p = (volatile int*)0x80000010;
  int  tmp0, tmp1, tmp2;
  void main(void)
  {
      tmp0 = *p;
      *p   = 1234;
      tmp1 = *p;
      *p   = 5678;
      tmp2 = *p;
  }

I watched tmp0,tmp1,tmp2 by debugger, but these values '0' (sometimes'-1409474866').

I checked HALCoGen settings.

 - Mpu setting Region 6 Configuration is
    checked 'Enable Mpu Region'
    Base Address : 0x80000000
    Size : 128_MB
    End Address : 0x87ffffff
    no check Disable Sub-Region 0 to 7
    Type : STRONGLYORDERD_SHAREABLE
    Permission : PRIV_RW_USER_RW_EXEC
 - No EMIF setting tab

What can I do to access SDRAM?
Please help me!