I/O Instruction 6-21
Table Relative
Treatsthe alternate jump address as a relative jump and
fetches the device ID,synchronous offset, and
synchronous period indirectly. The valuein bits [23:0] of
the first four bytes of the SCRIPTS instruction is added
to the data structure base address to form the fetch
address.
Sel Select with ATN/ 24
This bit specifies whether SATN/is asser ted during the
selection phase when the LSI53C810A is executing a
Select instruction. When operating in Initiator mode, set
this bit for the Select instruction. If this bit is set on any
other I/O instruction, an illegal instruction interrupt is
generated.
ENDID Encoded SCSI Destination ID [18:16]
This 3-bit field specifies the destination SCSI ID foran I/O
instruction.
CC 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.
Setting 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 Target mode.Setting this bit
with a Set instruction configures the LSI53C810A as a
target device (this sets bit 0 of the SCSI Control Zero
(SCNTL0) register). Clearing this bit with a Clear
instruction configures the LSI53C810A as an Initiator
device (this clears bit 0 of the SCSI Control Zero
(SCNTL0) register).
Command Table Offset
Absolute Jump Offset