In system calibration of wake up timer

摘要

A wireless transceiver includes receiver front-end circuitry for processing an ingoing radio frequency (RF) signal to produce an in-going digital signal to a processor connected to receive the in-going digital signal. The processor includes sync word determination logic configured to identify a received sync word or other event or connection point and to subsequently generate an event determination signal. A low power oscillator produces low frequency pulses to a first counter. A crystal oscillator that produces higher frequency pulses to a second counter is used for the last portion of the desired sleep time for greater resolution. Thus, a calibration controller receives pulse counts from at least one of the first and second counters and determines a period between a common event of subsequent beacon signals or connection events and determines wake up times based on the received pulse counts from at least one of the first and second counters.

主权项

1. A wireless transceiver, comprising:
receiver front end wireless circuitry for processing an ingoing radio frequency (RF) signal to produce an in-going digital signal; a processor coupled to receive the in-going digital signal, the processor including event determination logic configured to identify an event and to subsequently generate an event determination signal; a first oscillator that generates oscillation pulses; a first counter that counts the oscillation pulses of the first oscillator in response to the event determination signal to produce first pulse counts; and a calibration controller that receives the first pulse counts from the first counter and the event determination signal and determines a sleep time based on the first pulse counts from the first counter in relation to subsequent event determination signals.