Hierarchical power distribution and power management scheme for a single chip mobile processor

A hierarchical power distribution methodology that enables more than dozen power domains in a chip and a power management scheme using 20 power domains are described. This method can achieve very low leakage current in the partial active mode of a single chip mobile processor. The single chip mobile processor embedded three CPU's that is baseband processor, application processor, and multi-media processor. In the "waiting for calling" mode of the mobile handsets, application processor and multi-media processor part can be power-off. This chip can power off these power domains although the some of baseband parts are actively operating.. Many new techniques for multiple power domains in the chip are described.This paper describes the output of two projects. (1) Fundamental circuits research on hierarchical power domain = joint research by Hitachi, Ltd. and Renesas Technology Corp.[4] (2) LSI design for one chip mobile processor = joint development by NTT DoCoMo Inc. and Renesas Technology Corp.[5].