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Avago Technologies LSI53C876E User Manual

Page 210

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5-20

SCSI SCRIPTS Instruction Set

Direct
Uses the device ID and physical address in the
instruction.

Table Indirect
Uses the physical jump address, but fetches data using
the table indirect method.

Relative
Uses the device ID in the instruction, but treats the
alternate address as a relative jump.

Table Relative
Treats the alternate jump address as a relative jump and
fetches the device ID, synchronous offset, and
synchronous period indirectly. Adds the value in bits
[23:0] of the first four bytes of the SCRIPTS instruction to
the data structure base address to form the fetch
address.

Sel

Select with ATN/

24

This bit specifies whether SATN/ is asserted during the
selection phase when the LSI53C876 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.

Command

ID

Not Used

Not Used

Absolute Alternate Address

Command

Table Offset

Absolute Alternate Address

Command

ID

Not Used

Not Used

Absolute Jump Offset

Command

Table Offset

Alternate Jump Offset