SCSI Registers
4-99
Register: 0xBC
SCSI Control Four (SCNTL4)
Read/Write
This register is automatically loaded when a Table Indirect Select or
Reselect SCRIPTS instruction is executed.
U3EN
Ultra160 Transfer Enable
7
Setting this bit enables Ultra160 transfers. This bit will
force all SCSI Block Move SCRIPTS instructions for ST
Data-In or ST Data-Out phases to become DT Data-In or
DT Data-Out phases.
AIPCKEN
AIP Checking Enable
6
Setting this bit enables the AIP (Asynchronous
Information Protection) checking of the upper byte lane of
protection information during Command, Status, and
Message phases. By default, AIP codes are generated
on the SCSI bus during all asynchronous transfers. To
disable this feature set bit 3, the Disable AIP Code
Generation bit, in
R
Reserved
[5:4]
XCLKH_DT
Extra Clock of Data Hold on DT Transfer Edge
3
Setting this bit adds a clock of data hold to synchronous
DT SCSI transfers on the DT edge. This bit only impacts
DT transfers as it affects data hold to the DT edge.
Setting this bit reduces the synchronous transfer send
rate but does not reduce the transfer rate at which the
LSI53C1000 can receive inbound REQs, ACKs or data.
Refer to
and
for a summary of
available transfer rates and to
through
for examples of how the XCLKH bits function.
Note:
This bit does not affect CRC timings.
XCLKH_ST
Extra Clock of Data Hold on ST Transfer Edge
2
Setting this bit adds a clock of data hold to synchronous
DT or ST SCSI transfers on the ST edge. This bit impacts
7
6
5
4
3
2
1
0
U3EN
AIPCKEN
R
XCLKH_DT XCLKH_ST XCLKS_DT XCLKS_ST
0
0
0
0
0
0
0
0
Содержание LSI53C1000
Страница 6: ...vi Preface...
Страница 16: ...xvi Contents...
Страница 28: ...1 12 Introduction...
Страница 234: ...4 124 Registers...
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Страница 350: ...6 76 Specifications Figure 6 42 LSI53C1000 329 Ball Grid Array Bottom view...
Страница 352: ...6 78 Specifications...
Страница 360: ...A 8 Register Summary...
Страница 376: ...IX 12 Index...