LSI SYM8953U Manual De Usuario
3.75 pc
10.25 pc
11.25 pc
38.25 pc
4.333 pc
48.583 pc
52.5 pc
34.5 pc
44.25 pc
Interface Descriptions
1-5
1.3.3 Ultra2 SCSI Technology
The SYM8953U fully supports Ultra2 SCSI. Ultra2 SCSI is an extension
of the SCSI Parallel Interface 2 and 3 (SPI-2 and SPI-3) family of
standards. SCSI2 expands the bandwidth of the SCSI bus, allowing
faster synchronous data transfers.
of the SCSI Parallel Interface 2 and 3 (SPI-2 and SPI-3) family of
standards. SCSI2 expands the bandwidth of the SCSI bus, allowing
faster synchronous data transfers.
For the internal bus, special impedance SCSI ribbon cables are specified
for operation with Ultra and Ultra2 SCSI devices. You must consider the
total length of the bus cables and the number of devices on the SCSI
bus when setting up your system. Make sure that your SCSI cables are
rated for standard SCSI (Fast, Ultra, and Ultra2) environments.
for operation with Ultra and Ultra2 SCSI devices. You must consider the
total length of the bus cables and the number of devices on the SCSI
bus when setting up your system. Make sure that your SCSI cables are
rated for standard SCSI (Fast, Ultra, and Ultra2) environments.
has a detailed
explanation of SCSI bus connections.
1.3.4 LVD Link Technology
To support greater device connectivity and a longer SCSI cable, the
SYM8953U features LVD Link technology, the LSI Logic implementation
of Universal LVD SCSI. LVD Link transceivers provide the inherent
reliability of differential SCSI, and a long-term migration path to faster
SCSI transfer rates.
SYM8953U features LVD Link technology, the LSI Logic implementation
of Universal LVD SCSI. LVD Link transceivers provide the inherent
reliability of differential SCSI, and a long-term migration path to faster
SCSI transfer rates.
The LVD Link transceivers reduce the power needed to drive the SCSI
bus, so that the I/O drivers can be integrated directly into the chip. LVD
Link technology lowers the amplitude of noise reflections and allows
higher transmission frequencies.
bus, so that the I/O drivers can be integrated directly into the chip. LVD
Link technology lowers the amplitude of noise reflections and allows
higher transmission frequencies.
The LVD Link transceivers operate in LVD and SE modes. They also
allow the chip to detect a High Voltage Differential (HVD) signal when the
chip is mistakenly connected to external HVD transceivers. When
connected, the SYM53C895A chip automatically detects signal type,
based on the voltage detected. It automatically switches to the SE or LVD
mode, as appropriate. All bus devices must be LVD or SE. If a HVD
device is detected, the board puts the SCSI bus in the high impedance
state and shuts down.
allow the chip to detect a High Voltage Differential (HVD) signal when the
chip is mistakenly connected to external HVD transceivers. When
connected, the SYM53C895A chip automatically detects signal type,
based on the voltage detected. It automatically switches to the SE or LVD
mode, as appropriate. All bus devices must be LVD or SE. If a HVD
device is detected, the board puts the SCSI bus in the high impedance
state and shuts down.
1.3.4.1 Benefits of LVD Link
LVD Link, supported by the SYM53C895A, is a signaling technology that
increases the reliability of SCSI data transfers over longer distances than
supported by SE SCSI. The low current requirements of LVD allow direct
increases the reliability of SCSI data transfers over longer distances than
supported by SE SCSI. The low current requirements of LVD allow direct