Avago Technologies LSI53C1000R - Manual (Page 274)

5-32 SCSI SCRIPTS Instruction Set
Version 2.2 Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.
CD Compare Data 18
When this bit is set, the first byte received from the SCSI
data bus (contained in the
SCSI First Byte Received (SFBR) register) is compared
with the Data to be Compared Field in the Transfer Control
instruction. The Wait for Valid Phase bit controls when this
compare occurs. The Jump if True/False bit determines
the condition (true or false) to branch on.
CP Compare Phase 17
When the LSI53C1000R is in the initiator mode, this bit
controls phase compare operations. When this bit is set,
the SCSI phase signals (latched by SREQ/) are
compared to the Phase Field in the Transfer Control
instruction. If they match, the comparison is true. The
Wait for Valid Phase bit controls when the compare
occurs. When the LSI53C1000R is operating in the target
mode and this bit is set, it tests for an active SCSI SATN/
signal.
VP Wait for Valid Phase 16
If the Wait for Valid Phase bit is set, the LSI53C1000R
waits for a previously unserviced phase before comparing
the SCSI phase and data.
If the Wait for Valid Phase bit is cleared, the
LSI53C1000R compares the SCSI phase and data
immediately.
MC Data Compare Mask [15:8]
The Data Compare Mask allows a SCRIPT to test certain
bits within a data byte. During the data compare, if any
mask bits are set, the corresponding bit in the
SCSI First Byte Received (SFBR) data byte is ignored.
For instance, a mask of 0b01111111 and data compare
value of 0b1XXXXXXX allows the SCRIPTS processor to
determine whether or not the high order bit is set while
ignoring the remaining bits.
Bit 19
Result of
Compare
Action
0 False Jump Taken
0 True No Jump
1 False No Jump
1 True Jump Taken