Embedded control problems, Thumb, and the ARM7TDMI

Abstract

This article discusses an architectural innovation from ARM known as Thumb. High-end embedded control applications such as cell-phones, disk drives, and modems are demanding more performance from their controllers whilst still requiring low costs. By implementing a second "compressed" instruction set, Thumb reduces RISC code size and hence provides 32-bit ARM RISC performance at 8/16-bit system cost.The article starts with a description of the problems of embedded control and then discusses the Thumb solution and its implementation. Typical application areas and competitive benchmarking are also covered.