Irredundant address bus encoding techniques based on adaptive codebooks for low power

The power dissipation at the off-chip bus is a significant part of the overall power dissipation in digital systems. This paper presents irredundant address bus encoding methods which reduce signal transitions on the instruction address buses by using adaptive codebook methods. These methods are based on the temporal locality and spatial locality of instruction address. Since applications tend to JUMP/BRANCH to limited sets of addresses, proposed encoding methods assign the least signal transition codes to the addresses of JUMP/BRANCH operations in the past. Our encoding methods reduce the signal transitions on the instruction address buses by an average of 88%.