RFID tags enforcing persistence while powered
AssigneeImpinj, Inc.
InventorsTheron Stanford, Christopher J. Diorio
Life of this patent
Estimating the term…
Abstract
RFID tags may compensate for non-RFID power sources by automatically enforcing data or state persistence even while powered. A tag may measure a time interval between successive detected modulated reader transmissions. If the interval exceeds a minimum time, then the tag may deassert a protocol flag, erase data, and/or change tag operating states, even if the tag would normally not perform these actions while powered.
Claims20
A Radio Frequency Identification (RFID) integrated circuit (IC) configured to deassert an asserted protocol flag that, while the IC has sufficient power to maintain the protocol flag value, would otherwise remain asserted, the IC comprising:
- a demodulator block configured to demodulate reader commands;
- and
- a processing block coupled to the demodulator block and configured to:
- receive, via the demodulator block, a first reader command;
- assert the protocol flag in response to receiving the first reader command;
- and
- while the IC has sufficient power to operate:
- measure a time interval since receiving a first reader signal;
- and
- deassert the asserted protocol flag when the measured time interval exceeds a threshold without the IC receiving a second reader signal.
A Radio Frequency Identification (RFID) integrated circuit (IC) configured to erase volatile stored data that, while the IC has sufficient power to maintain the volatile stored data, would otherwise be retained, the IC comprising:
- a volatile memory configured to store the data;
- a demodulator block configured to demodulate reader commands;
- and
- a processing block coupled to the memory and the demodulator block and configured to:
- receive, via the demodulator block, a first reader command;
- store data in the memory in response to receiving the first reader command;
- and
- while the IC has sufficient power to operate:
- measure a time interval since receiving a first reader signal;
- and
- erase the stored data when the measured time interval exceeds a threshold without the IC receiving a second reader signal.
A Radio Frequency Identification (RFID) integrated circuit (IC) configured to transition from a first operating state to a second operating state when the IC, while having sufficient power to maintain an operating state, would otherwise remain in the first operating state, the IC comprising:
- a demodulator block configured to demodulate reader commands;
- and
- a processing block coupled to the demodulator block and configured to:
- receive, via the demodulator block, a first reader command;
- enter to the first operating state in response to receiving the first reader command;
- and
- while the IC has sufficient power to operate:
- measure a time interval since receiving a first reader signal;
- and
- transition from the first operating state to the second operating state when the measured time interval exceeds a threshold without the IC receiving a second reader signal.
Dependencies are inferred from the claim text.