TMS320F28377D: CSM Reading

Part Number: TMS320F28377D

I am trying to read CSM OTP area of after following the unlocking procedure but not able to read the programmed values correctly. (See Lines 21 to 23)

It returns ALL_0's any idea why ? Here's the snipped of the code  

Also, I am sure the password is correct, we have been using the same function to unlock the protected area successfully to perform write erase operations. 

void DCSMUnsecureZone_D()
{
    int i;
    volatile long int *CSM = (volatile long int *)0x5F010;  // CSM register file
    volatile long int *CSMPWL = (volatile long int *)0x78028;  // CSM password file
    volatile long int *OTP_Ptr = (volatile uint16_t *)0x78020;  // CSM password file

    volatile int tmp;

    EALLOW;
    // Dummy read of CSM password file required from unsecure zone to unlock DCSM
    for(i = 0; i < 4; i++) {
        tmp = *CSMPWL++;
    }

    *CSM++ = PASSWORD; //DcsmZ1Regs.Z1_CSMKEY0
    *CSM++ = PASSWORD; //DcsmZ1Regs.Z1_CSMKEY1
    *CSM++ = PASSWORD; //DcsmZ1Regs.Z1_CSMKEY2
    *CSM++ = PASSWORD; //DcsmZ1Regs.Z1_CSMKEY3

    ptr_shared_data_to_user->DebugReg[3] = OTP_Ptr[0];
    ptr_shared_data_to_user->DebugReg[4] = OTP_Ptr[4];
    ptr_shared_data_to_user->DebugReg[5] = OTP_Ptr[8];

    EDIS;


}

 Thanks