Data Sheet
SYM53C860
Single-Chip High-Performance PCI-Ultra SCSI (Fast-20) I/O Processor
Ultra SCSI (Fast-20) technology doubles the I/O bandwidth to 20 MB/s
Builds upon proven technology--a pin-for-pin replacement for the industry standard
SYM53C810 and SYM53C810A
Easy migration minimizes schedule and design risk
Provides new features for enhanced PCI performance and flexibility
The SYM53C860 includes all of the features of the SYM53C810A with added support
for Ultra SCSI (Fast-20) transfers, enabling the chip to transfer SCSI data at up to 20
MB/s across an 8-bit SCSI bus. Fast-20 is an extension of the SCSI-3 standard that
expands the bandwidth of the SCSI bus and allows faster synchronous SCSI transfer
rates. When enabled, Fast-20 approximately doubles the synchronous transfer rates of
Fast SCSI-2. The advantage of Symbios Fast-20 is that it significantly improves SCSI
bandwidth, while preserving existing hardware and software investments. The
SYM53C860 provides full SCSI-2 capabilities, including command queuing, and
features Symbios TolerANTTM SCSI driver and receiver technology, for reliable
operation in all cabling environments. It is designed to connect gluelessly to the
Peripheral Component Interconnect (PCI) bus, performing burst transfers on the bus in
excess of 110 MB/s.
The SYM53C860 and its available companion host adapter, the SYM8600SP, along
with the Symbios SCSI Device Management System (SDMS) software, provide a total
Ultra SCSI (Fast-20) solution in PC and workstation environments. The SYM8600SP is
a low-cost host bus adapter which meets all the requirements of Plug-and-Play SCSI
with SCAM (SCSI Configured AutoMatically) support, as well as the requirements and
recommendations for the Windows 95 logo program. SDMS is the complete software
package designed by Symbios to support the entire SYM53C8XX family of PCI-SCSI
controllers plus a wide range of SCSI peripheral devices.
PCI performance enhancements on the SYM53C860 include the SCRIPTSTM (the
Symbios-developed SCSI programming language) instruction prefetch which, when
enabled, permits fetching four or eight double words of instructions or instruction
operands. By pre-fetching instructions, the SYM53C860 makes more efficient use of the
PCI system bus by reducing the PCI bus overhead requirements. In addition, the part
supports the PCI Cache Line Size Register with programmable alignment logic and
automatic burst sizing, allowing system architects to maximize their cache-based
system performance through efficient use of PCI Memory Read Line, Memory Read
Multiple, and Memory Write and Invalidate access cycles. Other selectable features that
can be activated include:
IRQ Disable, allowing users to better control the times when their system can
receive interrupts
SCSI Selected as ID register, improving SCRIPTS coding and system tracking
Load and Store instruction allows the programmer a new, efficient instruction option
to load data directly to/from memory and from/to an internal register, reducing the
number of I/O instructions to implement a SCRIPTS task
Features & Benefits
Performance
Performs high-speed single-ended SCSI bus transfers up to 20 MB/s synchronous
Fast-20 transfers and 7 MB/s asynchronous transfers
SCRIPTS Instruction Prefetch
Load and Store instruction
Support for PCI Cache Line Size Register
Functions as full 32-bit PCI DMA bus master
Bursts 2, 4, 8, or 16 long words of data across PCI bus using 80-byte DMA FIFO
Ease-Of-Use
Pin-for-pin replacement for SYM53C810 and SYM53C810A devices
Minimal software and hardware modifications required for Fast-20 support
Compact 100-pin PQFP reduces board space requirements
Provides SCAM (SCSI Configured AutoMatically) functionality
Direct PCI-to-SCSI connection
Compiler-compatible with existing SYM53C7XX & SYM53C8XX SCRIPTS
Fully supported by SDMS software for complete PC-based operating system support
Flexibility
Selectable IRQ disable
SCSI Selected as ID Register
Support for both 3.3 volt and 5 volt PCI interfaces
High-level programming interface (SCSI SCRIPTS)
Allows tailored SCSI sequences to be executed from main memory
Accommodates changes in the logical I/O interface definition
Low-level access to all registers and all SCSI bus signals
Compatibility
SDMS software supports the Advanced SCSI Protocol interface (ASPI)
Full complement of Symbios SCSI SCRIPTS PCI development tools available
BIOS and driver support for hard disk, tape, CD-ROM, and removable media
peripherals for all of the major operating systems, including: DOS, Windows 3.X,
Windows 95, Windows NT, OS/2 (including Warp), Novell NetWare, SCO UNIX,
UnixWare
Related SYM53C860 Product
SYM8600SP Host Adapter
SYM53C860 System Diagram
Symbios, SCRIPTS, SDMS, and TolerANT are trademarks of Symbios Inc
.
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