Bitfields for AMD-640 PCI Arbitration Control 1 register:
Bit(s)	Description	)
 7	arbitration priority
	0 = fixed (high-to-low is REQ1#, REQ2#, REQ3#, REQ4#, PREQ#, and CPU)
	1 = fair (round-robin) arbitration
 6	arbitration mode
	0 arbitrate at end of REQ#
	1 arbitrate at end of each FRAME# (allows pre-emption by a
	  higher-priority initiator)
 5-4	reserved (0)
 3-0	number of idle time periods of 32 PCI clocks before arbitration is
	  forced (0000 disables timeout)
SeeAlso: #00983,#01008,#01010