Design Guide

System Overview

Intel

855GM/855GME Chipset Platform Design Guide 31

2.3.2. Intel 855GME Chipset Graphics Memory Controller Hub

(GMCH)

All chipset and graphics features of Intel 855GM chipset GMCH is supported in Intel 855GME chipset

GMCH. This section lists the additional enhancements.

• Integrated System Memory DRAM controller

 Supports up to two double-sided SO-DIMMs (four rows populated) with unbuffered

PC1600/PC2100/PC2700 DDR-SDRAM (ECC is not supported)

 Support for memory self refresh in C3

• Integrated graphics core frequency

 Display / Render Core frequency up to 250 MHz

• Integrated graphics engine

 Frame Buffer Compression

 Bi-Cubic Filtering supported

 Video Mixer Rendering support

 Linear Gamma Blending for VMR

• Backlight Image Adaptation Technology

 Allows image enhancement by direct control of the backlight inverter through the PWM signal

• Package/Power

 VCC, VCCASM, VCCHL, VCCAHPLL, VCCAGPLL, VCCADPLLA, VCCADPLLB (1.35V)

2.3.2.1. Accelerated Graphics Port (AGP) Interface

The 855GME platform is configurable to support either the AGP interface for external graphics or the

DVO interface when using internal graphics.

• Supports AGP 2.0 data transfers

• Supports a single AGP (1X/2X/4X) device (either via a connector or on the motherboard)

• Only supports 1.5-V VDDQ for AGP electricals

• PCI semantic (FRAME# initiated) accesses to DRAM are snooped

• AGP semantic (PIPE# and SBA) traffic to DRAM is not snooped on the PSB and is therefore not

coherent with the CPU caches

• High priority access support

• Delayed transaction support for AGP reads that cannot be serviced immediately

• AGP Busy/Stop Protocol support

• Support for D3 Hot and Cold Device states

• AGP Clamping and Sense Amp control