Patent ID: 7157899

Claim:
An electric power meter comprising: (a) a quantizer including a quantizer input and a quantizer output, said quantizer converting an instantaneous amplitude of an analog signal at said quantizer input to a digital amplitude signal at said quantizer output, said analog signal representing one of a voltage waveform and a current waveform; (b) a sampler to capture and hold an instantaneous amplitude of said analog signal at said quantizer input in response to assertion of a sampling signal; (c) a data processor to read said digital amplitude signal at said quantizer output in response to execution by said data processor of a program instruction included in an interrupt service routine, said data processor initiating an interrupt process including a period of interrupt latency in response to assertion of an interrupt request, and executing said program instruction to read said digital signal in response to assertion of said sampling signal; and (d) a sampling timer asserting said interrupt request and said sampling signal, said interrupt request being asserted a time period at least as great as said interrupt latency prior to assertion of said sampling signal.