National Semi and ARM Release PWI Technology

October 13, 2003 by Jeff Shepard

National Semiconductor Corp. (Santa Clara, CA) and ARM released the new PowerWise™ Interface (PWI) technology, jointly promoted as an open-standard interface for system power management, which enables rapid deployment of advanced power management solutions in hand-held electronic devices by providing an open, industry-wide standard for the interconnect between digital processors and power management integrated circuits (PMIC).

The PWI specification defines a two-wire serial interface connecting the integrated power controller of a system-on-chip processor system with a PMIC voltage regulation system that enables system designers to adjust the supply and threshold voltages on digital processors. The PWI specification defines the required functionality in the PWI-slave. The PWI command set includes PMIC operating state control, register read, register write and voltage adjust commands. The specification additionally provides provision for user-defined registers in the PWI slave.

The PWI specification is now available from National Semiconductor and ARM for adoption on a royalty-free and license-free basis. Companies interested in adopting the specification can do so by submitting an adopter’s agreement, available for download at