摘要:
A Radio Frequency (RF) transponder (tag), method, and system, whereby the tag has a low current tag oscillator, the oscillation frequency of the tag oscillator set by RF signal from a base station.
摘要:
A radio frequency identification (RFID) transponder (tag) integrated circuit includes “on-chip” test circuitry. The test circuitry includes a serially-loaded test register. The test register controls the execution of on-chip tests. Such tests may include the testing of EEPROM circuitry included within the IC, the testing of analog circuitry, or the testing of digital circuitry included within the IC.
摘要:
The present invention provides an RFID transponder that includes a state holding cell that maintains the present state of the RFID transponder during temporary losses of power. After power is restored to the RFID transponder, the state holding cell restores the present state to the RFID transponder so that transactions with an RFID interrogator can continue without having re-transmit redundant commands. The RFID transponder further comprises an RF front end adapted to receive an interrogating RF signal. An analog circuit is coupled to the RF front end and is adapted to recover analog signals from the received interrogating RF signal. The analog circuit provides state information defining a desired state of the RFID transponder corresponding to the analog signals. A digital state machine is coupled to the analog circuit and adapted to execute at least one command in accordance with the state information. A memory is coupled to the digital state machine and is adapted to store and retrieve digital data responsive to the at least one command executed by the digital state machine. A power capacitor is coupled to the RF front end and derives a voltage rectified from the interrogating RF signal to charge the power capacitor. The power capacitor thereby provides electrical power for the analog circuit, the digital state machine and the memory. The state holding cell is coupled to the analog circuit and the digital state machine and is adapted to maintain the state information during a loss in power provided by the power capacitor due to lapse in receipt of the interrogating RF signal by the RF front end.
摘要:
A system and method for providing power from a source of stored electrical energy to a microcomputer for a user established "ride-through" period of time after a disruption in the primary power supply for the microcomputer. If the primary power supply is not restored within the ride-through time period the system performs an orderly shut down of computer applications. Should stored energy reserves run low during the primary power disruption, the system instead performs an abbreviated, critical application shut down. Following application shut down, or upon the expiration of a user established "shut down" time period, the system performs an orderly shut down of computer system operations and thereafter removes all power from the computer. Shut down and shut off procedures are canceled, if possible, upon restoration of the primary power supply.