LSI U40HVD 1.3Interface Descriptions, 1.2.3Board Characteristics, 1.3.1The PCI Interface, 1.3.2The SCSI Interface

1.2.3Board Characteristics

The board characteristics for the LSIU40HVD are:

•PCI board dimensions,

190 x 96.52 mm (7.50 x 3.80 inches)

•Universal 32-bit card edge connector

1.3Interface Descriptions

This section provides a more detailed explanation about the PCI

Interface, the SCSI Interface, and Ultra SCSI.

1.3.1The PCI Interface

PCI is a high-speed standard local bus for interfacing a number of I/O components to the processor and memory subsystems in a high-end PC. The PCI functionality for the LSIU40HVD is contained within the LSI53C876 PCI to SCSI I/O Processor chip. The LSI53C876 chip connects directly to the PCI bus and generates timing protocol in compliance with the PCI specification.

The PCI interface operates as a 32-bit DMA bus master. The connection is made through the edge connector J1 (see Figure 2.1). The signal definitions and pin numbers conform to the PCI Local Bus Specification Revision 2.1 standard. The LSIU40HVD conforms to the PCI universal signaling environment for a 5 V or 3.3 V PCI bus.

1.3.2The SCSI Interface

The SCSI functionality for the LSIU40HVD is contained within the LSI Logic LSI53C876. The LSI53C876 chip connects directly to the two SCSI buses and generates timing and protocol in compliance with the SCSI standard.

The SCSI interface on the LSIU40HVD operates as a 16-bit, synchronous or asynchronous, differential bus, and supports Ultra SCSI protocols and 16-bit arbitration. Each interface is made through the connectors J2 and J3 (for Channel A), or J5 and J6 (for Channel B). Connectors J2 and J5 are 68-pin high-density, right-angle receptacles.

Interface Descriptions 1-3