AN-1460 Emulating the PowerWise Interface Using GPIOs and Software (Rev. A)
PowerWise Interface (PWI) compatible Energy Management Units (EMUs) from Texas Instruments are flexible, highly integrated, and digitally programmable system power managers that can be used in a variety of applications. Controlling or programming the EMU in the system is achieved using the PWI open-standard (www.pwistandard.org).
The method for using the PWI1.0 connected EMU in systems with a processor containing a hardware PWI master like the Advanced Power Controller (APC) is obvious (http://www.ti.com/ww/en/analog/power_management/powerwise-avs.shtml).
Using the PWI connected EMU in a system where the processor does not contain a hardware-based PWI master is straight forward using a GPIO port and a PWI protocol software driver.