Avago Technologies LSI53C1010R User Manual
Page 271
I/O Instructions
5-23
Version 2.2
Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.
register). Clearing this bit
with a Clear instruction configures the LSI53C1010R 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 asserts SACK/ on the SCSI bus. The
Clear instruction deasserts SACK/ on the SCSI bus. The
corresponding bit in the
SCSI Output Control Latch (SOCL)
register is set or cleared depending on the instruction
used. Because SACK/ is an initiator signal, it is not
asserted on the SCSI bus unless the LSI53C1010R 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/.
The Set instruction asserts SATN/ on the SCSI bus. The
Clear instruction deasserts SATN/ on the SCSI bus. The
corresponding bit in the
SCSI Output Control Latch (SOCL)
register is set or cleared depending on the instruction
used. Because SATN/ is an initiator signal, it is not
asserted on the SCSI bus unless the LSI53C1010R 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
[2:0]