Opcode encoding for low power embedded systems

In this paper, we propose two encoding schemes for reducing the amount of switching on the instruction memory, which is one of the biggest sources of power dissipation. We have targeted embedded systems with an external bus interface (EBI) unit with 16-bit and 8-bit external memory interface systems (such as mobile phones). Our schemes are based on instruction code field encoding. The major advantage of our encoding schemes stems from the fact that they only involve minor modifications to the EBI, and do not require any changes to the processor core.