Intel 820E User Manual

Page of 239
  
Intel
®
 820E Chipset 
R
 
 
 
Design Guide 
 
15 
1.3. System 
Overview 
The Intel 820E chipset is designed for Intel
®
 
Pentium
®
 III microprocessors and is the first chipset to 
support the integrated LAN capability and expanded USB capability. It supports the 4
×
 capability of the 
AGP 2.0 Interface Specification and it supports the 400 MHz Direct RDRAM* interface. The 400 MHz, 
16-bit, double-clocked Direct RDRAM interface provides 1.6-GB/s access to main memory. To provide 
more efficient communication between chipset components, the hub interface component interconnect is 
designed into the Intel 820E chipset. 
Support of AGP 4
×
, 400 MHz Direct RDRAM and the hub interface provides a balanced system 
architecture for the Pentium III processor, minimizing bottlenecks and increasing system performance. By 
increasing memory bandwidth to 1.6 GB/s by means of 400 MHz Direct RDRAM and by increasing the 
graphics bandwidth to 1 GB/s by means of AGP 4
×
, the Intel 820E chipset delivers the data throughput 
necessary to take advantage of the high performance provided by the powerful Pentium III processors. 
In addition, the Intel 820E chipset architecture enables security and manageability infrastructures through 
the Firmware Hub (FWH)component. 
The ACPI-compliant Intel 820E chipset platform can support the Full-On, Stop Grant, Suspend to RAM, 
Suspend to Disk, and Soft-Off power management states. Through the use of the integrated LAN 
functions, the Intel 820E chipset also supports Wake on LAN* for remote administration and 
troubleshooting. 
The Intel 820E chipset architecture eliminates the need for the ISA expansion bus traditionally integrated 
into the I/O subsystem of Intel chipsets. This eliminates many conflicts experienced when installing 
hardware and drivers into legacy ISA systems. The elimination of ISA provides true plug and play for the 
Intel 820E chipset platform. Traditionally, the ISA interface was used for audio and modem devices. The 
addition of AC’97 allows the OEM to use software-configurable AC’97 audio and modem 
encoders/decoders (codecs), instead of traditional ISA devices. The 82801BA ICH2 component expands 
the support of AC’97 to include up to 6-channel audio. The ISA bus can be implemented with a PCI-to-
ISA bridge from an external component supplier. 
The Intel 820E chipset contains two core components: the Memory Controller Hub (MCH) and the I/O 
Controller Hub 2 (ICH2). The MCH integrates the 133 MHz processor system bus controller, an AGP 
2.0 controller, a 400 MHz Direct RDRAM controller, and a high-speed hub interface for communication 
with the ICH2. The ICH2 integrates an Ultra ATA/100 controller, two USB host controllers, an LPC 
interface controller, an FWH Flash BIOS interface controller, a PCI interface controller, an AC’97 
digital controller, an integrated LAN controller, and a hub interface for communication with the MCH. 
The Intel 820E chipset provides the data buffering and interface arbitration required to ensure that the 
system interfaces operate efficiently and provide the system bandwidth necessary to obtain peak 
performance with the Pentium III processor.