LSI LSI53C1000, Technical Manual

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LSI53C1000 PCI to Ultra160 SCSI Controller 5-1
Chapter 5
SCSI SCRIPTS
Instruction Set
After power-up and initialization, the LSI53C1000 can operate in the low
level register interface mode, or use SCSI SCRIPTS.
With the low level register interface, the user has access to the DMA
control logic and the SCSI bus control logic. An external processor has
access to the SCSI bus signals and the low level DMA signals, which
allow creation of complicated board level test algorithms. The low level
interface is useful for backward compatibility with SCSI devices that
require certain unique timings or bus sequences to operate properly.
The following sections describe the benefits and use of SCSI SCRIPTS.
•
Section 5.1, “SCSI SCRIPTS”
•
Section 5.2, “Block Move Instructions”
•
Section 5.3, “I/O Instructions”
•
Section 5.4, “Read/Write Instructions”
•
Section 5.5, “Transfer Control Instructions”
•
Section 5.6, “Memory Move Instructions”
•
Section 5.7, “Load and Store Instructions”
5.1 SCSI SCRIPTS
To operate in the SCSI SCRIPTS mode, the LSI53C1000 requires only
a SCRIPTS start address. The start address must be at a Dword (four
byte) boundary. This aligns all the following SCRIPTS at a Dword
boundary since all SCRIPTS are 8 or 12 bytes long. Instructions are
fetched until an interrupt instruction is encountered, or until an
unexpected event (such as a hardware error) causes an interrupt to the
external processor.