Bitfields for AMD-640 DRAM Timing register:
Bit(s)	Description	)
 7-6	RAS# precharge time
	00 = 2T (for 50ns DRAM) [T = HCLK period]
	01 = 3T (60ns)
	10 = 4T (70ns)
	11 = 6T
 5-4	RAS# pulse width
	00 = 3T (for 50ns DRAM)
	01 = 4T (60ns)
	10 = 5T (70ns)
	11 = 6T
 3-2	CAS# pulse width
	FPM: 00=1T, 01=2T, 10=3T, 11=4T
	EDO: 00=4T, 01=1T, 10=2T, 11=3T
 1	write pulse width (0 = 1T, 1 = 2T)
 0	delay from column address to CAS# (0 = 1T, 1 = 2T)
SeeAlso: #00983,#00994