I/O Instructions
5-21
R
Reserved
[15:11]
CA
Set/Clear Carry
10
This bit is used in conjunction with a Set or Clear
instruction to set or clear the Carry bit. Setting this bit
with a Set instruction asserts the Carry bit in the ALU.
Clearing this bit with a Clear instruction deasserts the
Carry bit in the ALU.
TM
Set/Clear Target Mode
9
This bit is used in conjunction with a Set or Clear
instruction to set or clear the target mode. Setting this bit
with a Set instruction configures the LSI53C1000 as a
target device (this sets bit 0 of the
register). Clearing this bit with a Clear
instruction configures the LSI53C1000 as an initiator
device (this clears bit 0 of the SCNTL0 register).
R
Reserved
[8:7]
A
Set/Clear SACK/
6
This bit is used in conjunction with a Set or Clear
instruction to assert or deassert SACK/.
The Set instruction is used to assert SACK/ on the SCSI
bus. The Clear instruction is used to deassert SACK/ on
the SCSI bus. The corresponding bit in the
register is set or cleared depend-
ing on the instruction used. Since SACK/ is an initiator
signal, it is not asserted on the SCSI bus unless the
LSI53C1000 is operating as an initiator.
The Set/Clear SCSI ACK/, ATN/ instructions are used
after message phase Block Move operations to give the
initiator the opportunity to assert attention before
acknowledging the last message byte. For example, if the
initiator wishes to reject a message, it issues an Assert
SCSI ATN instruction before a Clear SCSI ACK
instruction.
R
Reserved
[5:4]
ATN
Set/Clear SATN/
3
This bit is used in conjunction with a Set or Clear
instruction to assert or deassert SATN/.
Содержание LSI53C1000
Страница 6: ...vi Preface...
Страница 16: ...xvi Contents...
Страница 28: ...1 12 Introduction...
Страница 234: ...4 124 Registers...
Страница 314: ...6 40 Specifications This page intentionally left blank...
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...