AM79C974中文资料超威半导体数据手册PDF规格书

GENERAL DESCRIPTION

The PCnet-SCSI combination Ethernet and 8-bit Fast SCSI controller with a 32-bit PCI bus interface is a highly integrated Ethernet-Fast SCSI system solution designed to address high-performance system application requirements. This single-chip is a flexible bus-mastering device that can be used in many applications, including network- and SCSI-ready PCs, printers, fax modems, and bridge/router designs. The bus-master architecture provides high data throughput in the system and low CPU and system bus utilization. The PCnet-SCSI controller is fabricated with AMD’s advanced low-power CMOS process to provide low operating and standby current for power sensitive applications.

DISTINCTIVE CHARACTERISTICS

PCI Features

■ Direct glueless interface to 33 MHz, 32-bit PCI local bus

■ 132 Mbyte/s burst DMA transfer rate

■ Compliant to PCI local bus Specification Revision 2.0

Ethernet Features

■ Supports ISO 8802-3 (IEEE/ANSI 802.3) and Ethernet Standards

■ High-performance Bus Master architecture with integrated DMA Buffer Management Unit for low CPU and bus utilization

■ Individual 136-byte transmit and 128-byte receive FIFOs provide frame buffering for increased system latency

■ MicrowireTM EEPROM interface supports jumperless design

■ Integrated Manchester Encoder/Decoder

■ Provides integrated Attachment Unit Interface (AUI) and 10BASE-T transceiver with automatic port selection

■ Automatic Twisted-Pair receive polarity detection and automatic correction of the receive polarity

■ Dynamic transmit FCS generation programmable on a frame-by-frame basis

■ Internal/external loopback capabilities

■ Supports the following types of network interfaces:

— AUI to external 10BASE2, 10BASE5, 10BASE-T or 10BASE-F MAU

— Internal 10BASE-T transceiver with Smart Squelch to Twisted-Pair medium

SCSI Features

■ Compliant to ANSI standards X3.131 – 1986 (SCSI-1) and X3.131 – 199X (SCSI-2)

■ Fast 8-bit SCSI-2 10 Mbyte/s synchronous or 7 Mbyte/s asynchronous data transfer rate

■ SCSI specific Bus Mastering DMA engine (32-bit address/data)

■ 96-byte DMA FIFO for low bus latency

■ On-chip state machine to control the SCSI sequences in hardware

■ Integrated industry standard Fast SCSI-2 core

■ Single-Ended 48 mA outputs to drive the SCSI bus directly

■ Support for Scatter-Gather DMA data transfers

■ Hooks in silicon and software to enable disk drive spin down for power savings

General Features

■ Software compatible with AMD’s Am79C960 PCnet-ISA, Am79C961 PCnet-ISA+, Am79C965 PCnet-32, Am79C970 PCnet-PCI register and descriptor architecture

■ Plug-in and software compatible with AMD’s PCSCSI family of SCSI controllers for PCI

■ NAND Tree test mode for connectivity testing on printed circuit boards

■ Single +5 V power supply operation

■ Low-power, CMOS design with sleep modes for both Ethernet and SCSI controllers allows reduced power consumption for critical battery powered applications and ‘Green PCs’

■ Fully static design for low frequency and power operation

■ 132-pin PQFP package