Avago Technologies LSI53C876E - Manual (Page 129)

SCSI Registers 4-35
Where:
MO[4:0] Max SCSI Synchronous Offset [4:0]
These bits describe the maximum SCSI synchronous
offset used by the LSI53C876 SCSI function when
transferring synchronous SCSI data in either initiator or
target mode.
Table 4.5 describes the possible
combinations and their relationship to the synchronous
data offset used by the LSI53C876 SCSI function. These
bits determine the LSI53C876 SCSI function’s method of
transfer for Data-In and Data-Out phases only; all other
information transfers occur asynchronously.
SXFERP Synchronous transfer period.
SSCP SCSI synchronous core period.
SSCF SCSI synchronous core frequency.
ExtCC Extra clock cycle of data setup.
Table 4.3 Examples of Synchronous Transfer
Periods for SCSI-1 Transfer Rates
CLK
(MHz)
SCSI CLK
÷
SCNTL3
Bits [6:4] XFERP
Synch.
Transfer
Period (ns)
Synch. Transfer
Rate (Mbytes/s)
40
ч
4 4 200 5
80
ч
2 4 200 5
Table 4.4 Example Transfer Periods for Fast SCSI
and Wide Ultra SCSI Transfer Rates
CLK
(MHz)
SCSI CLK
÷
SCNTL3
Bits [6:4] XFERP
Synch.
Transfer
Period (ns)
Synch.
Transfer Rate
(Mbytes/s)
80
ч
1 4 50 20
80
ч
2 4 100 10
40
ч
1 4 100 10