SCSI Registers
4-23
WATN
Select with SATN/ on a Start Sequence
4
When this bit is set and the LSI53C896 SCSI function is
in the initiator mode, the SATN/ signal is asserted during
selection of a SCSI target device. This is to inform the
target that the LSI53C896 SCSI function has a message
to send. If a selection time-out occurs while attempting to
select a target device, SATN/ is deasserted at the same
time SSEL/ is deasserted. When this bit is cleared, the
SATN/ signal is not asserted during selection. When
executing SCSI SCRIPTS, this bit is controlled by the
SCRIPTS processor, but manual setting is possible in low
level mode.
EPC
Enable Parity Checking
3
When this bit is set, the SCSI data bus is checked for odd
parity when data is received from the SCSI bus in either
the initiator or target mode. If a parity error is detected,
bit 0 of the
SCSI Interrupt Status Zero (SIST0)
register is
set and an interrupt may be generated.
If the LSI53C896 SCSI function is operating in the
initiator mode and a parity error is detected, assertion of
SATN/ is optional, but the transfer continues until the
target changes phase. When this bit is cleared, parity
errors are not reported.
R
Reserved
2
AAP
Assert SATN/ on Parity Error
1
When this bit is set, the LSI53C896 SCSI function
automatically asserts the SATN/ signal upon detection of
a parity error. SATN/ is only asserted in the initiator
mode. The SATN/ signal is asserted before deasserting
SACK/ during the byte transfer with the parity error. Also
set the Enable Parity Checking bit for the LSI53C896
SCSI function to assert SATN/ in this manner. A parity
error is detected on data received from the SCSI bus.
If the Assert SATN/ on Parity Error bit is cleared or the
Enable Parity Checking bit is cleared, SATN/ is not
automatically asserted on the SCSI bus when a parity
error is received.
TRG
Target Mode
0
This bit determines the default operating mode of the
LSI53C896 SCSI function. The user must manually set
*
Содержание LSI53C896
Страница 6: ...vi Preface...
Страница 16: ...xvi Contents...
Страница 88: ...2 62 Functional Description...
Страница 112: ...3 24 Signal Descriptions...
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Страница 338: ...6 70 Specifications Figure 6 40 LSI53C896 329 BGA Bottom View...
Страница 340: ...6 72 Specifications...
Страница 346: ...A 6 Register Summary...
Страница 362: ...IX 12 Index...