Cirrus Logic CS8900A - Manual (Page 10)

10 DS271F5
CS8900A
Crystal LAN™ Ethernet Controller
CIRRUS LOGIC PRODUCT DATASHEET
• On-chip LED ports can be used for either
optional LEDs, or as programmable out-
puts.
1.3 Key Features and Benefits
1.3.1 Very Low Cost
The CS8900A is designed to provide the low-
est-cost Ethernet solution available for embed-
ded applications, portable motherboards, non-
ISA bus systems and adapter cards. Cost-sav-
ing features include:
• Integrated RAM eliminates the need for ex-
pensive external memory chips.
• On-chip 10BASE-T filters allow designers
to use simple isolation transformers in-
stead of more costly filter/transformer
packages.
• The serial EEPROM port, used for configu-
ration and initialization, eliminates the need
for expensive switches and jumpers.
• The CS8900A is designed to be used on a
2-layer circuit board instead of a more ex-
pensive multilayer board.
• The 8900A-based solution offers the small-
est footprint available, saving valuable
printed circuit board area.
• A set of certified software drivers is avail-
able at no charge, eliminating the need for
costly software development.
1.3.2 High Performance
The CS8900A is a full 16-bit Ethernet control-
ler designed to provide optimal system perfor-
mance by minimizing time on the ISA bus and
CPU overhead per frame. It offers equal or su-
perior performance for less money when com-
pared to other Ethernet controllers. The
CS8900A’s PacketPage architecture allows
software to select whichever access method is
best suited to each particular CPU/ISA-bus
configuration. When compared to older I/O-
space designs, PacketPage is faster, simpler
and more efficient.
To boost performance further, the CS8900A
includes several key features that increase
throughput and lower CPU overhead, includ-
ing:
• StreamTransfer cuts up to 87% of inter-
rupts to the host CPU during large block
transfers.
• Auto-Switch DMA allows the CS8900A to
maximize throughput while minimizing
missed frames.
• Early interrupts allow the host to prepro-
cess incoming frames.
• On-chip buffering of full frames cuts the
amount of host bandwidth needed to man-
age Ethernet traffic.
1.3.3 Low Power and Low Noise
For low power needs, the CS8900A offers
three power-down options: Hardware Stand-
by, Hardware Suspend, and Software Sus-
pend. In Standby mode, the chip is powered
down with the exception of the 10BASE-T re-
ceiver, which is enabled to listen for link activ-
ity. In either Hardware or Software Suspend
mode, the receiver is disabled and power con-
sumption drops to the micro-ampere range.
In addition, the CS8900A has been designed
for very low noise emission, thus shortening
the time required for EMI testing and qualifica-
tion.
1.3.4 Complete Support
The CS8900A comes with a suite of software
drivers for immediate use with most industry
standard network operating systems. In addi-
tion, complete evaluation kits and manufactur-
ing packages are available, significantly
reducing the cost and time required to produce
new Ethernet products.