
Benefits of SURElink (Ultra3 SCSI Domain Validation)
1-5
signals. Data is clocked on both rising and falling edges of the request
and acknowledge signals. Double-edge clocking doubles data transfer
speeds without increasing the clock rate.
Ultra3 SCSI also includes CRC which offers higher levels of data
reliability by ensuring complete integrity of transferred data. CRC is a
32-bit scheme, referred to as CRC-32. CRC is guaranteed to detect all
single bit errors, any two bits in error, or any combination of errors within
a single 32-bit range.
AIP is also supported by the SYM53C1010, protecting all nondata
phases, including command, status, and messages. CRC, along with AIP,
provides end-to-end protection of the SCSI I/O.
An advantage of Ultra3 SCSI is that it significantly improves SCSI
bandwidth while preserving existing hardware and software investments.
The primary software changes required are to enable the chip to perform
synchronous negotiations for Ultra3 SCSI rates and to enable the clock
quadrupler. Ultra3 SCSI uses the same connectors as Ultra SCSI and
Ultra2 SCSI.
Chapter 2, “Functional Description”
contains more
information on migrating an Ultra SCSI or Ultra2 SCSI design to an
Ultra3 SCSI design.
1.3 Benefits of SURElink (Ultra3 SCSI Domain Validation)
SURElink represents the very latest SCSI interconnect management
solution. It ensures robust and low risk Ultra3 SCSI implementations by
extending the Domain Validation guidelines documented in the ANSI T10
SPI-3 specifications. Domain Validation verifies that the system is
capable of transferring data at Ultra3 speeds, allowing it to renegotiate to
lower speed and bus width if necessary. SURElink is the software control
for the manageability enhancements in the SYM53C1010 PCI to Dual
Channel Ultra3 SCSI Multifunction Controller. Fully integrated in the
SDMS software solution, SURElink provides Domain Validation at boot
time as well as throughout system operation. SURElink extends to the
DMI (Desktop Management Interface) based System Management
components of SDMS, providing the network administrator remote
management capability.
SURElink Domain Validation provides 3 levels of integrity checking: Basic
(level 1), Enhanced (level 2) and Margined (level 3). The basic check