5-4
SCSI SCRIPTS Instruction Set
new byte counts and starting locations in main memory. In this manner,
the LSI53C1000 performs scatter/gather operations on data without
requiring help from the host program, generating a host interrupt, or
programming of an external DMA controller.
provides an overview of SCRIPTS operation.
Figure 5.1
SCRIPTS Overview
5.2 Block Move Instructions
For Block Move instructions, bits 5 and 4 (SIOM and DIOM) in the
register determine whether the source/destination
address resides in memory or I/O space. When data is moved onto the
System Processor
System Memory
(or Internal RAM)
SCSI Initiator Write Example
select ATN0, alt_addr
move 1, identify_msg_buf, when MSG_OUT
move 6, cmd_buf, when CMD
move 512, data_buf, when DATA_OUT
move 1, stat_in_buf, when STATUS
move 1, msg_in_buf, when MSG_IN
move SCNTL2 & 7F to SCNTL2
clear ACK
wait disconnect alt2
int 10
Data Structure
Message Buffer
Command Buffer
Data Buffer
Status Buffer
LSI53C1000
SCSI
Bus
Write DSP
Fetch
SCRIPTS
Data
(Data is not fetched across system bus if
internal RAM is enabled.)
S
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s
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m
B
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Содержание LSI53C1000
Страница 6: ...vi Preface...
Страница 16: ...xvi Contents...
Страница 28: ...1 12 Introduction...
Страница 234: ...4 124 Registers...
Страница 314: ...6 40 Specifications This page intentionally left blank...
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Страница 350: ...6 76 Specifications Figure 6 42 LSI53C1000 329 Ball Grid Array Bottom view...
Страница 352: ...6 78 Specifications...
Страница 360: ...A 8 Register Summary...
Страница 376: ...IX 12 Index...