5-14 Operating Registers
R Reserved 4
MO[3:0] Max SCSI Synchronous Offset [3:0]
These bits describe the maximum SCSI synchronous
offset used by the LSI53C810A when transferring
synchronous SCSI data in either the initiator or target
mode. Table 5.5 describes the possible combinations and
their 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 Examples of Synchronous Transfer Periods and Rates
for SCSI-1 (Cont.)
SCLK
(MHz)
SCF ÷
SCNTL3
Bits [6:4]
XFERP
SXFER
Bits [7:5]
Synch.
Send Rate
(Mbytes/s)
Synch.
Send
Period (ns)
Synch.
Receive
Rate
(Mbytes/s)
Synch.
Receive
Period (ns)
Table 5.4 Examples of Synchronous Transfer Periods and
Rates for Fast SCSI
SCLK
(MHz)
SCF ÷
SCNTL3
Bits [6:4]
XFERP
SXFER
Bits
[7:5]
Synch.
Send Rate
(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