Patent ID: 8130046

Claim:
A device comprising: a memory; a transceiver; and a processor coupled to the memory and the transceiver, wherein the transceiver comprises: a radio frequency voltage controlled oscillator (RF VCO) with coarse frequency tuning and fine frequency tuning; a fine frequency tuning circuit with a continuous analog control voltage configured to adjust the RF VCO in small frequency steps; a coarse frequency tuning circuit configured to receive a reference clock signal, a phase locked loop signal, and an output interrupt signal, and further configured to select a coarse tuning code from among a plurality of coarse tuning codes and transmit the selected tuning code to the processor, wherein receipt of the output interrupt signal causes the coarse frequency tuning circuit to adjust the RF VCO frequency in large frequency steps; digital-to-analog converters configured to generate analog voltage thresholds Vmin and Vmax based on digital inputs; a comparator circuit, coupled to an analog control voltage input of the RF VCO and to the digital-to-analog converters and configured to compare the analog control voltage input of the RF VCO with Vmin and Vmax; and a comparator circuit configured to generate the output interrupt signal to initiate RF VCO coarse frequency calibration when the fine frequency tuning circuit voltage input to the RF VCO is either above Vmax or below Vmin, wherein the processor is configured to: receive the generated interrupt signal; generate a command signal to initiate coarse tuning upon receipt of the interrupt signal; transmit the command signal to the transceiver to initiate coarse tuning; receive the selected coarse tuning code from the transceiver; and store the selected coarse tuning code in the memory.