Avago Technologies LSI53C1010 - Manual (Page 33)

Assembling SCSI SCRIPTS 2-3
2.3 Assembling SCSI SCRIPTS
The SCSI SCRIPTS are assembled with the LSI Logic Assembler
(NASM), a DOS command line driven assembler that supports LSI Logic
SCSI SCRIPTS processors. NASM assembles SCSI SCRIPTS for
inclusion in SCSI device driver software programs. NASM is described in
detail in
Chapter 4, “Using the LSI Logic Assembler NASM™.”
The SCSI SCRIPTS programs are created with any text editor that
generates ASCII files. These text files must be transformed from their text
form into the SCRIPTS processors instruction language before they can
be executed by the SCRIPTS processor. This is accomplished by running
the test file through NASM. NASM generates an output file (
.out ) that is
Command During this phase, the initiator can send a command
in the form of a command descriptor block (CDB) to
the target buffer. MOVE WHEN
CMD MOVE WITH
CMD
Data In/Out Data In and Data Out phases are used to send data
to the initiator or to the target and are used
dependent on the information transferred during the
Command phase. This phase is optional. For
example, a Test Unit Ready command does not
require a data transfer. MOVE MOVE
Status During this phase, the initiator receives status
information from the target about the previously
executed CDB. MOVE WHEN
STATUS MOVE WITH
STATUS
Message-In During this phase, the initiator will receive messages
from the target. These messages can acknowledge
or reject previously sent initiator messages. They
also can provide other information like queuing,
disconnect, or parity errors. MOVE WHEN
MSG_IN MOVE WITH
MSG_IN
Disconnect This phase is used to end the initiator's connection
with the bus. WAIT
DISCONNECT DISCONNECT
After successful completion of an I/O operation and
a request for disconnect, the bus returns to the Bus
Free state, indicating that it is now available. WAIT
DISCONNECT DISCONNECT
Table 2.1 SCSI Protocol and SCRIPTS Instructions (Cont.)
Bus Phase Definition
SCRIPTS
Instruction
(Initiator role)
SCRIPTS
Instruction
(Target role)