Patent ID: 8234482

Claim:
An apparatus for interfacing between subsystems within a portable computer, the apparatus comprising, within the portable computer: a main processor; an embedded controller for executing instructions; a first subsystem comprising a plurality of components, each of the plurality of components selected from a group consisting of: an accelerometer, a keyboard controller, a mouse controller, and a battery level indicator; a second subsystem comprising a plurality of components, each of the plurality of components selected from a group consisting of: a battery charging circuit, a keyboard light controller, a display backlight controller, and a display controller, wherein the embedded controller directly receives a first signal from the first subsystem, the signal being generated by a sensor that comprises at least one of a keyboard, a mouse, the accelerometer and the battery level indicator, and directly transfers a second signal derived from the first signal to the second subsystem to control a corresponding one of keyboard lights, display backlight, and pointer coupled to the second subsystem, wherein the second signal is not transferred to the main processor; and persistent memory directly coupled to the embedded controller and not to the main processor, the persistent memory including a table of functions for execution by the embedded controller for executing instructions in a function in response to the first signal from the first subsystem to generate the second signal to the second subsystem based upon the first signal, the table of functions further storing an instruction to select a battery controller and protocol information for communication with the battery controller, the instruction causing the embedded controller to select the battery controller for communication.