5-14 Operating Registers

R Reserved 4MO[3:0] Max SCSI Synchronous Offset [3:0]These bits describe the maximum SCSI synchronousoffset used by the LSI53C810A when transferringsynchronous SCSI data in either the initiator or targetmode.Table 5.5 describes the possible combinations andtheir relationship to the synchronous data offset used by
40 2 4 5 200 5 200
37.50 1.5 4 6.25 160 6.25 160
33.33 1.5 4 5.55 180 5.55 180
25 1 4 6.25 160 6.25 160
20 1 4 5 200 5 200
16.67 1 4 4.17 240 4.17 240
Table 5.3 Examplesof Synchronous Transfer Periods and Ratesfor SCSI-1 (Cont.)
SCLK
(MHz)
SCF ÷
SCNTL3
Bits [6:4]
XFERP
SXFER
Bits [7:5]
Synch.
SendRate
(Mbytes/s)
Synch.
Send
Period (ns)
Synch.
Receive
Rate
(Mbytes/s)
Synch.
Receive
Period (ns)
Table 5.4 Examplesof Synchronous Transfer Periods andRates for Fast SCSI
SCLK
(MHz)
SCF ÷
SCNTL3
Bits [6:4]
XFERP
SXFER
Bits
[7:5]
Synch.
SendRate
(Mbytes/s)
Synch.
Send
Period
(ns)
Synch.
Receive
Rate
(Mbytes)
Synch.
Receive
Period (ns)
66.67 1.5 4 11.11 90 11.11 90
66.67 1 5 8.88 112.5 11.11 90
50 1 4 12.5 80 12.5 80
50 1 5 10 100 12.5 80
40 1 4 10 100 10.0 100
37.50 1 4 9.375 106.67 9.35 106.67
33.33 1 4 8.33 120 8.33 120
25 1 4 6.25 160 6.25 160
20 1 4 5 200 5 200
16.67 1 4 4.17 240 4.17 240