Avago Technologies LSI53C825AE User Manual
Page 200
5-16
SCSI SCRIPTS Instruction Set
Wait Select Instruction
1. If the LSI53C825A is selected, it fetches the next
instruction from the address pointed to by the
register.
2. If reselected, the LSI53C825A fetches the next
instruction from the address pointed to by the 32-bit
jump address field stored in the
register. Manually set the LSI53C825A to
Initiator mode when it is reselected.
3. If the CPU sets the SIGP bit in the
register, the LSI53C825A aborts the Wait
Select instruction and fetches the next instruction from
the address pointed to by the 32-bit jump address
field stored in the
register.
Set Instruction
When the SACK/ or SATN/ bits are set, the
corresponding bits in the
register are set. Do not set SACK/ or SATN/
except for testing purposes. When the target bit is set,
the corresponding bit in the
register is also set. When the carry bit is set, the
corresponding bit in the Arithmetic Logic Unit (ALU) is
set.
Note:
None of the signals are set on the SCSI bus in Target
mode.
Clear Instruction
When the SACK/ or SATN/ bits are cleared, the
corresponding bits are cleared in the
register. Do not set SACK/ or
SATN/ except for testing purposes. When the target bit is
cleared, the corresponding bit in the
register is cleared. When the carry bit is
cleared, the corresponding bit in the ALU is cleared.
Note:
None of the signals are cleared on the SCSI bus in the
Target mode.
illustrates the I/O Instruction register.