Bitfields for AMD-645 XD Power-Up Strap Options register:
Bit(s)	Description	)
 7-4	Keyboard RP16-RP13
 3	reserved (0)
 2	enable internal RTC
 1	enable internal PS/2 mouse
 0	enable internal keyboard controller
Note:	the default value of this register is latched from external pins at
	  power-up
SeeAlso: #01011