Feasibility study for communication over Power Distribution Networks of microprocessors

In this paper, we explore use of the Power Distribution Network (PDN) of a microprocessor as a communication channel for testing, debug, and diagnosis purposes. Feasibility of the proposed communication method is studied through direct measurements of microprocessor PDNs. Decoupling capacitors attached to the package make the PDN a low pass filter. However, the parasitic inductance of a decoupling capacitor becomes more significant beyond the self-resonant frequency, and our measurements on Intel microprocessor PDNs indicate that pass bands exist at frequencies beyond several 100 MHz. Impulse ultra wideband signals are a good candidate for communications over PDNs.