Avago Technologies LSI53C1010R User Manual
Page 147
SCSI Registers
4-29
Version 2.2
Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.
CON
Connected
4
This bit is automatically set any time the LSI53C1010R
SCSI function is connected to the SCSI bus as an initiator
or as a target. It is set after the LSI53C1010R SCSI
function successfully completes arbitration or when it has
responded to a bus initiated selection or reselection. This
bit is also set after the chip wins simple arbitration when
operating in low level mode. When this bit is cleared, the
LSI53C1010R SCSI function is not connected to the
SCSI bus.
The CPU can force a connected or disconnected
condition by setting or clearing this bit.
RST
Assert SCSI RST/ Signal
3
Setting this bit asserts the SRST/ signal. The SRST/
output remains asserted until this bit is cleared. The
25
µ
s minimum assertion time defined in the SCSI
specification must be timed out by the controlling
microprocessor or a SCRIPTS loop.
AESP
Assert Even SCSI Parity (Force Bad Parity)
2
When this bit is set, the LSI53C1010R SCSI function
asserts even parity. It forces a SCSI parity error on each
byte sent to the SCSI bus from the chip. If parity checking
is enabled, then the LSI53C1010R SCSI function checks
data received for odd parity. This bit is used for diagnostic
testing and is cleared for normal operation.
IARB
Immediate Arbitration
1
Setting this bit causes the SCSI core to begin arbitration
immediately when a Bus Free phase is detected following
an expected SCSI disconnect. This bit is useful for
multithreaded applications. The ARB[1:0] bits in
are set for full arbitration
and selection before setting this bit.
Arbitration is retried until won. At that point, the
LSI53C1010R SCSI function holds SBSY and SSEL
asserted, and waits for a select or reselect sequence.
The Immediate Arbitration bit is cleared automatically
when the selection or reselection sequence is completed
or times out.