5 flexibility, Flexibility – LSI 53C875A User Manual
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LSI53C875A Benefits Summary
1-7
•
Up to one megabyte of add-in memory support for BIOS and
SCRIPTS storage.
•
Reduced SCSI development effort.
•
Compiler-compatible with existing LSI53C7XX and LSI53C8XX
family SCRIPTS.
•
Direct connection to PCI and SCSI SE.
•
Development tools and sample SCSI SCRIPTS available.
•
Five GPIO pins.
•
Maskable and pollable interrupts.
•
Wide SCSI, A or P cable, and up to 15 devices supported.
•
Three programmable SCSI timers: Select/Reselect,
Handshake-to-Handshake, and General Purpose. The time-out
period is programmable from 100
µ
s to greater than 25.6 seconds.
•
Software for PC-based operating system support.
•
Support for relative jumps.
•
SCSI Selected as ID bits for responding with multiple IDs.
1.4.5 Flexibility
The LSI53C875A provides:
•
High level programming interface (SCSI SCRIPTS).
•
Ability to program local and bus flash memory.
•
Selectable 112 or 944 byte DMA FIFO for backward compatibility.
•
Tailored SCSI sequences execute from main system RAM or internal
SCRIPTS RAM.
•
Flexible programming interface to tune I/O performance or to adapt
to unique SCSI devices.
•
Support for changes in the logical I/O interface definition.
•
Low level access to all registers and all SCSI bus signals.
•
Fetch, Master, and Memory Access control pins.
•
Separate SCSI and system clocks.