4-86
Registers
R
Reserved
6
HSC
Halt SCSI Clock
5
Asserting this bit causes the internal divided SCSI clock
to come to a stop in a glitchless manner. This bit is used
for test purposes or to lower I
DD
during a power-down
mode. Refer to
Chapter 2, “Functional Description,”
for
operation of the SCSI clock quadrupler.
DSI
Disable Single Initiator Response
4
If this bit is set, the LSI53C1000 ignores all bus-initiated
selection attempts that employ the single-initiator option
from SCSI-1. In order to select the LSI53C1000 while this
bit is set, the LSI53C1000 SCSI ID and the initiator’s
SCSI ID must both be asserted. Assert this bit in SCSI-2
systems so that a single bit error on the SCSI bus is not
interpreted as a single initiator response.
R
Reserved
3
TTM
Timer Test Mode
2
Asserting this bit facilitates testing of the selection
time-out, general purpose, and handshake-to-handshake
timers by greatly reducing all three time-out periods.
Setting this bit starts all three timers. If the respective bits
in the
SCSI Interrupt Enable One (SIEN1)
register are
asserted, the LSI53C1000 generates interrupts at
time-out. This bit is intended for internal manufacturing
diagnosis and should not be used in normal operation.
CSF
Clear SCSI FIFO
1
Setting this bit causes the “full flags” for the SCSI FIFO
to be cleared. This empties the FIFO. This bit is
self-clearing. In addition to the SCSI FIFO pointers, the
SIDL, SODL, and SODR full bits in the
and
are cleared.
R
Reserved
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 318: ...6 44 Specifications This page intentionally left blank...
Страница 344: ...6 70 Specifications This page intentionally left blank...
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...