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 selectively deassert an asserted protocol flag that, absent such selective deassertion or a reader command to deassert the asserted protocol flag, would remain asserted while the IC has sufficient power to operate, the IC comprising:
- a demodulator block configured to:
- detect modulated reader transmissions;
- and
- demodulate reader commands from at least a subset of the modulated reader transmissions;
- 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:
- determine whether a time interval between detecting a first modulated reader transmission and detecting a second modulated reader transmission exceeds a minimum time;
- and
- if the time interval exceeds the minimum time, then deassert the asserted protocol flag despite the IC having sufficient power to operate.
A Radio Frequency Identification (RFID) integrated circuit (IC) configured to selectively erase stored data that, absent such selective erasing or a reader command to erase the data, would be retained while the IC has sufficient power to operate, the IC comprising:
- a memory configured to store the data;
- a demodulator block configured to:
- detect modulated reader transmissions;
- and
- demodulate reader commands from at least a subset of the modulated reader transmissions;
- 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:
- determine whether a time interval between detecting a first modulated reader transmission and detecting a second modulated reader transmission exceeds a minimum time;
- and
- if the time interval exceeds the minimum time, then erase the stored data despite the IC having sufficient power to operate.
A Radio Frequency Identification (RFID) integrated circuit (IC) configured to selectively transition between a first and a second operating states whereby, absent such selective transitioning or a reader command to transition states, the IC would remain in the first operating state while the IC has sufficient power to operate, the IC comprising:
- a demodulator block configured to:
- detect modulated reader transmissions;
- and
- demodulate reader commands from at least a subset of the modulated reader transmissions;
- and
- a processing block coupled to the demodulator block and configured to:
- receive, via the demodulator block, a first reader command;
- transition to the first operating state in response to receiving the first reader command;
- and
- while the IC has sufficient power to operate:
- determine whether a time interval between detecting a first modulated reader transmission and detecting a second modulated reader transmission exceeds a minimum time;
- and
- if the time interval exceeds the minimum time, then transition from the first operating state to the second operating state despite the IC having sufficient power to operate.
Dependencies are inferred from the claim text.