Cirrus Logic CS8900A - Manual (Page 9)

DS271F5 9
CS8900A
Crystal LAN™ Ethernet Controller
CIRRUS LOGIC PRODUCT DATASHEET
high level of integration allow System Engi-
neers to design a complete Ethernet circuit
that occupies as little as 1.5 square inches of
PCB area (Figure 1). In addition, the
CS8900A’s power-saving features and CMOS
design make it a perfect fit for power-sensitive
portable and desktop PCs. Motherboard de-
sign options include:
• An EEPROM can be used to store node-
specific information, such as the Ethernet
Individual Address and node configuration.
• The 20 MHz crystal oscillator may be re-
placed by a 20 MHz clock signal.
1.2.2 Ethernet Adapter Cards
The CS8900A’s highly efficient PacketPage
architecture, with StreamTransfer™
and Auto-
Switch DMA options, make it an excellent
choice for high-performance, low-cost ISA
adapter cards (Figure 2). The CS8900A’s wide
range of configuration options and perfor-
mance features allow engineers to design
Ethernet solutions that meet their particular
system requirements. Adapter card design op-
tions include:
• A Boot PROM can be added to support
diskless applications.
• The 10BASE-T transmitter and receiver
impedance can be adjusted to support 100,
120, or 150 Ohm twisted pair cables.
• An external Latchable-Address-bus de-
code circuit can be added to operate the
CS8900A in Upper-Memory space.
RJ-45 10BASE-T CS8900A
I
S
A
EEPROM 20 MHz
XTAL
(2.0 sq. in.)
Figure 1. Complete Ethernet Motherboard Solution
CS8900A
EEPROM
Boot PROM
'245
20 MHz
XTAL
RJ-45
LED
Attachment
Unit
Interface
(AUI)
Figure 2. Full-Featured ISA Adapter Solution