RFID device with first clock for data acquisition and/or calibration of second clock

A Radio Frequency Identification (RFID) device, comprising:

• a crystal controlled first clock signal generator generating a first clock signal at a first frequency;
• a second clock signal generator generating a second clock signal at a second frequency that is higher than the first frequency;
• and
• an activate circuit;
• a sensor for taking a sensor reading at a rate of a real time clock signal;
• and
• logic for determining occurrence of a trigger condition based at least in part on the first clock signal,
• wherein the second clock signal generator is inactive until activated by the activate circuit,
• wherein the first clock signal is used to calibrate the second clock signal generator,
• logic for generating a digital calibration value when the second clock signal generator is calibrated using the first clock signal, the digital calibration value indicating a calibration setting of the second clock signal generator,
• wherein the second clock signal generator is used to modulate communication of the RFID device,
• wherein an action is performed upon determining the occurrence of the trigger condition,
• wherein the action is performed without activating the second clock signal generator,
• wherein the second clock signal generator is used to modulate communication of the RFID device.

A method for taking and transmitting a sensor reading, the method comprising:

• generating a first clock signal at a first frequency;
• generating a second clock signal at a second frequency that is higher than the first frequency;
• wherein the first clock signal is used to calibrate a generator of the second clock signal generator,
• wherein the second clock signal generator is used to modulate communication of the RFID device;
• generating a digital calibration value when the second clock signal generator is calibrated using the first clock signal, the digital calibration value indicating a calibration setting of the second clock signal generator;
• determining occurrence of a trigger condition based at least in part on the first clock signal;
• taking a sensor reading at a rate of a real time clock signal in response to the occurrence of the trigger condition, the real time clock signal being based on the first clock signal;
• and
• transmitting information about the sensor reading via a wireless link, wherein a modulation of the transmitting is based on a second clock signal that has a higher frequency than the first clock signal.

A method for taking a sensor reading on a Radio Frequency Identification (RFID) device, the method comprising:

• generating a first clock signal at a first frequency;
• independently generating a second clock signal at a second frequency higher than the first frequency;
• calibrating the second clock signal using the first clock signal;
• taking a sensor reading at a rate of a real time clock signal,
• wherein the first clock signal is used to calibrate a generator of the second clock signal generator;
• generating a digital calibration value when the second clock signal generator is calibrated using the first clock signal, the digital calibration value indicating a calibration setting of the second clock signal generator.