ARM/THUMB code compression for embedded systems

Abstract

The use of code compression in embedded systems based on standard RISC instruction set architectures (ISA) has been shown in the past to be of benefit in reducing overall system cost. The 16-bit THUMB ISA from ARM Ltd has a significantly higher density than the original 32-bits ARM ISA. In this paper we propose a new memory compression architecture, which employs a lossless data compression algorithm to achieve a further size reduction of around 20% on the THUMB code. We show that in some applications, the decompression can be performed in software on the main system processor without excessive processing time overheads.