StrongARM MCM Module

Type: Semester thesis
Student: George von Büren and Albert Wuersch

The StrongARM MCM is a Multi Chip Module computer core targeted for the use in portable or embedded systems. It was designed in a thesis at the Electronics Laboratory of ETH Zurich in cooperation with the ETH spin-off company u-blox. Currently a number of mobile and wearable applications are being implemented using this module. A new version optimized for wearable applications is planned.

1. Overview

The module integrates on a surface of 37.5 x 37.5 mm an Intel StrongARM SA-1100 Processor, two 64 Mbit Intel Strata Flash Chips, four 4Mbit Samsung Ultra Low Power SRAM Chip, a converter for the core voltage of the processor and the two crystals.

The 32-bit RISC SA-1100 Processor provides system support logic, multiple serial communication channels, a color/gray scale LCD controller, PCMCIA support for up to two sockets, and general-purpose I/O ports. Operating systems as WinCE, ArmLinux, JavaOS, Inferno and VxWorks run on this processor.

The module is realized in a mixed built-up technology using chips in CSPs and SMT. The StrongARM Processor, the Flash and the SRAM Memory are CSP with BGA . Compared to conventionally packaged parts, the StrongARM MCM reduces mechanical size by factor three. The StrongARM MCM can be soldered by its BGA interface directly on a PCB. This interconnection simplifies

the design of an application board and reduces the time to market.

2. Techbrief

 2.1 Features

• Intel StrongARM SA-1100 Processor,
• 190 MHz,
• 330 mW
• 16 MB Flash Memory: 2 Intel Strata Flash 64 Mbit
• 2 MB SRAM:  4 Samsung Ultra Low Power 4 Mbit
• Integrated Power Supply for Processor Core (1.5 V) On-Board Crystals 32.768 kHz and 3.6864 MHz
• Total Power Consumption: max. 500 mW
• 205-pin Ball Grid Array (BGA), Pitch 1.27 mm

 2.2 Substrate and Assembly Dimensions

• Substrate: 37.5 x 37.5 x 1 mm
• Height of BGA-Balls: 760 m
• Total Height (assembled): max. 4.3 mm
• 6 Layers: FR-4 Core with 2 Built-Up Layers on each side CSP ( BGA) and SMT