[LinuxBIOS] register_values question

This may sound like a dumb question but I am wondering.
In this statment from raminit.c in the sdram_set_registers function:
---------------------------------------------------------------
static const unsigned int register_values[] = {

/* CKDIS 0x8c disable clocks */
    PCI_ADDR(0, 0x00, 0, CKDIS), 0xffff0000, 0x0000ffff,
};
---------------------------------------------------------------
It is setting the register PCI_ADDR(0, 0x00, 0, CKDIS) from 0xffff0000  
to 0x0000ffff correct??

But what if I just want it use it's default register setting do I need  
to specify it??

If so, would it look something like this??
------------------------------------------------------
PCI_ADDR(0, 0x00, 0, CKDIS), 0xffff0000, 0xffff0000,
------------------------------------------------------

Thanks - Joe