
Functional Description
3–7
Digital Semiconductor 21174 Core Logic Chip
•
Supports PCI and CardBus interfaces
•
Supports an unlimited PCI burst
•
Supports PCI clock speed frequency from dc to 33 MHz; network operation with
PCI clock from 20 MHz to 33 MHz
•
Supports automatic loading of subvendor ID and CardBus card information
structure (CIS) pointer from serial ROM to configuration registers
•
Supports full-duplex operation on both MII/SYM and 10BASE-T ports
•
Provides MicroWire interface for serial ROM (1K and 4K EEPROM)
•
Supports three network ports: 10BASE-T (10 Mb/s), AUI (10 Mb/s), and MII/
SYM (10/100 Mb/s)
•
Supports IEEE 802.3 and ANSI 8802-3 Ethernet standards
For more information about the 21143, refer to the Digital Semiconductor 21143
PCI/CardBus 10/100-Mb/s Ethernet LAN Controller Data Sheet and the Digital
Semiconductor 21143 PCI/CardBus 10/100-Mb/s Ethernet LAN Controller Hard-
ware Reference Manual.
3.2.6 PCI- Ultra SCSI (Fast-20) I/O Processor Chip
•
Performs wide high-speed SCSI bus transfers in single-ended and differential
mode up to 40 MB/s synchronous Ultra SCSI (Fast-20) transfers and 14 MB/s
asynchronous transfers
•
SCRIPTS Instruction Prefetch
•
536-byte buffer allows burst length of up to 128 transfers
•
Load and Store instruction
•
4 KB static RAM for SCRIPTS instruction storage
•
32 additional Scratchpad registers for user-defined functions
•
Designed to provide a smooth migration path from existing Fast SCSI designs
•
Builds upon proven SCSI technologya pin-for-pin replacement for the wide
SCSI industry standard SYM53C825 and SYM53C825A
•
Provides new features for enhanced PCI performance and flexibility