Code Compression has been used to alleviate the memory requirements as well as to improve performance and/or minimize energy consumption. On the other hand, implementing security primitives on Embedded Systems is always costly in terms of area and performance. In this paper we present a code compression method, the IBC-EI (instruction based compression with encryption and integrity checking), tailored to provide integrity checking and encryption to secure processor-memory transactions. The principle is to keep the code compressed and ciphered in the memory, thus reducing the memory footprint and providing more information per memory access. For the Leon processor and a set of benchmarks from the Mediabench and MiBench suites the habitual overheads due to security trend to zero in comparison to a system without security neither compression.

Code compression has been shown to be an effective technique to reduce code size in memory constrained embedded systems. It has also been used as a way to increase cache hit ratio, thus reducing power consumption and improving performance. This paper proposes an approach to mix static/dynamic instruction profiling in dictionary construction, so as to best exploit trade-offs in compression ratio/performance. Compressed instructions are stored as variable-size indices into fixed-size codewords, eliminating compressed code misalignments. Experimental results, using the Leon (SPARCv8) processor and a program mix from MiBench and Mediabench, show that our approach halves the number of cache accesses and power consumption while produces compression ratios as low as 56%.

Code compression has been used to minimize the memory area requirement of embedded systems. Recently, performance improvement and energy consumption reduction are observed as a by-product of compression. In this paper we propose a novel technique for efficiently exploring the trade-offs involved in code compression. Our multiprofile approach to build dictionaries combines the best features of both static and dynamic program behaviors. The experiments with Mediabench and MiBench suites and the Leon (SPARCv8) processor reveal a compression ratio as low as 71% while performance speed-up reaches 1.5.