Benefits Of Pci-X; Benefits Of Ultra320 Scsi - LSI LSI53C1030 Technical Manual

1.3 Benefits of PCI-X

1.4 Benefits of Ultra320 SCSI

1-6
user significant development and maintenance effort since it is not
necessary to alter or redevelop the device driver when a revision of the
LSI53C1030 device or firmware occurs.
PCI-X doubles the maximum clock frequency of the conventional PCI
bus. The PCI-X Addendum to the PCI Local Bus Specification,
Revision 1.0a, defines enhancements to the proven PCI Local Bus
Specification, Revision 2.2. PCI-X provides more efficient data transfers
by enabling registered inputs and outputs, improves buffer management
by including transaction information with each data transfer, and reduces
bus overhead by restricting the use of wait states and disconnects. PCI-X
also reduces host processor overhead by providing a wide range of error
recovery implementations.
The LSI53C1030 supports up to a 133 MHz, 64-bit PCI-X bus and is
backward compatible with previous versions of the PCI/PCI-X
specification. The LSI53C1030 is a true multifunction PCI-X device and
presents a single electrical load to the PCI bus. The LSI53C1030 uses
a single REQ/-GNT/ pair to arbitrate for PCI bus mastership. Separate
interrupt signals for PCI Function [0] and PCI Function [1] allow
independent control of the two PCI functions.
Per the PCI-X addendum, the LSI53C1030 includes transaction
information with all PCI-X transactions to enable more efficient buffer
management schemes. Each PCI-X transaction contains a transaction
sequence identifier (Tag), the identity of the initiator, and the number of
bytes in the sequence. The LSI53C1030 clocks PCI-X data directly into
and out of registers, which creates a more efficient data path. The
LSI53C1030 increases bus efficiency since it does not insert wait states
after the initial data phase when acting as a PCI-X target and never
inserts wait states when acting as a PCI-X initiator.
Ultra320 SCSI is an extension of the SPI-4 draft specification that allows
faster synchronous SCSI data transfer rates than Ultra160 SCSI. When
enabled, Ultra320 SCSI performs 160 megatransfers per second
Introduction
Version 2.1 Copyright © 2001, 2002, 2003 by LSI Logic Corporation. All rights reserved.