Bitfields for AMD-640 CPU-to-PCI Flow Control 2 register:
Bit(s)	Description	)
 7	unsuccessful retry (16 or 64 times) has occurred (write-clear)
 6	retry timeout action
	0 retry continuously, recording status
	1 flush buffer; if reading, return FFFFFFFFh
 5-4	retry count and backoff
	00 retry twice, backoff processor
	01 retry 16 times, set bit 7 on failure
	10 retry four times, backoff processor
	11 retry 64 times, set bit 7 on failure
 3	discard failed data from write buffer when retry fails
 2	backoff processor if PCI read retry fails
 1	assert FRAME# one cycle earlier than indicated by offset 71h bit 1
 0	reduce TRDY#-to-BRDY# by one HCLK on processor reads of PCI target
SeeAlso: #00983,#01005,#01007