The Chipset Guide

Aladdin Pro II / M1621/ M15X3 AGP Chipset - 66/100 MHz Front Side Bus

Aladdin Pro is a new generation Pentium II class system chip set which continuously supports cost effective desktop PCs. It consists of two BGA packed chips, the M1621 and M1533 or M1543. The M1621 is an AGP, memory and I/O controller and a data path with multi-port buffers for data acceleration. With an external I/O APIC controller, it can support multiple Pentium II processors.

The M1533 provides a bridge between the PCI bus and ISA bus. It includes power management unit, ACPI, deep green function, 2-channel dedicated Ultra-33 IDE master controller, 2-port USB controller, SMBus controller, and PS2 Keyboard/Mouse controller. The M1543 integrates ACPI, green function, 2-channel dedicated Ultra-33 IDE Master controller, 2-port USB controller, SMBus controller, PS/2 keyboard/mouse controller and Super I/O (Floppy Disk Controller, 2 serial port/1 parallel port) support.

Aladdin Pro employs various techniques to improve the memory and I/O throughput to match up with the advanced super-scalar, super-pipelined Pentium II class processors. On the memory subsystem side, the Pentium II data bus utilization is minimized. The pipelined memory cycle design helps hidden precharge latency and refresh cycles. Different ways of configurations optimize the performance for a wide range of memory size. On the I/O subsystem side, deep buffers shadow the latency for both PCI devices initiated master read and write. To support the 3D graphics function, M1621 supports a 66 MHz graphics PCI bus, and 1x/2x AGP mode.

Reliability and performance are the keys to PC design. They are also the major targets of Aladdin Pro design for Pentium II. Parity protection over PCI bus and independent EC and ECC protection over memory subsystem is used. Programmable SMM address mapping is also provided.