Product Overview

M1681 is ALi's new generation of North bridge chip supporting the latest Intel® P4 processors. Interfaces with the P4 System bus, the M1681 Northbridge chipset provides high performance memory interfaces for both 200/266/333/400 DDR and 100/133 SDR memory. Supporting the PC3200 memory, which enables 3.2 GB/s peak bandwidth between the system memory and North bridge to boost system performance to the next level.

With AGP 1x/2x/4x/8x support, M1681 prepares system designers with enough headroom to interface with different graphics solutions to fulfill various market requirements. M1681 couples with M1563, a highly integrated South bridge chip, which brings a complete and cost-effective solution for PC system designers.

System Architecture

The system block diagram below shows ALi solution with M1681 and M1563. The highly integrated M1563 allows board designers to build cost-effective motherboard with rich features including USB, Ethernet MII, Ultra-66/100/ 133 IDE, AC' 97 2.1 Compliant CODEC, PS2 Keyboard/Mouse, LPC, ACPI, GPIO, and deep green function.

Processor Support

Supports all Pentium 4 family processors

2x addressing and 4x data transferring

64-bit data bus and 32-bit address

Support back to back read/write transfers

Support up to 12 deep in-Order Queue

4 way adaptive pre-fetching

Smart read/write recording

Support synchronous/ pseudo asynchronous/ fully asynchronous access of system memory

Memory Support

Support DDR SDRAM with 200, 266, 333, 400MHz

Supports SDR DRAM with 100, 133 MHz

Maximum bandwidth 3.2GB/s with DDR 400MHz

Support 64Mb, 128Mb, 256Mb, 512Mb, 1Gb, 2 Gb

technology x8/ x16 4 band device

Smart paging scheme achieving excellent hit rate

4 way ping pong access for gap-less data burst

Multi-band interleaving

High/ Low dynamic priority priority arbitration

Support both CBR-refresh and Self-refresh

Smart write buffering and reordering

Dynamic Power-Down and Self-Refresh power saving

Support LVTTL/ SSTL2 I/O signaling

Accelerated Graphics Port (AGP) Interface

Support AGP specification V2.0, V3.0

Support 533MHz 1.5V signaling

Support 1x/ 2x/ 4x/ 8x AGP data transfer

Support 1x/ 2x/ 4x/ 8x PCI fast write

Maximum bandwidth 2.1 GB/s

Support Coherent AGP to system memory read/ write

Support direct access of NLVM in system memory

Support dynamic I/O calibration

Support up to 128 entries translation look aside buffer for Graphic Address Remapping Table

28 entries Request quene

64 Quadwords read buffer

32 Quadword write buffer

Power Management

Support PC' 99 suspend to DRAM

Support ACPI 1.0b and legacy green functions

Internally dynamic clock down

Packaging

669-Ball 37.5mmx 37.5mm BGA Package