RFID TAG CHIPS AND TAGS COMPLYING WITH ONLY A LIMITED NUMBER OF REMAINING COMMANDS AND METHODS

• US 20080204195A1
• Filed: 02/21/2008
• Published: 08/28/2008
• Est. Priority Date: 02/21/2007
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Diorio, Christopher J., Khwaja, Omar, Hagen, Casey M.
• Granted Patent: US 8,354,917 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G06F 21/554 involving event detection and direct action
• CPC Class Codes: G06F 2221/2135 Metering
• CPC Class Codes: G06K 19/07309 Means for preventing undesired reading or writing from or onto record carriers
• CPC Class Codes: H04L 63/0492 by using a location-limited connection, e.g. near-field communication or limited proximity of entities
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32

Abstract

RFID tags and chips for RFID tags are capable of complying with only a limited number of remaining commands, and methods. In a number of embodiments, a counter is adjusted in association with receiving a command and complying with it. The tag complies until the counter reaches a limit, and then it can stop complying. Non-compliance can be by the tag becoming quiet, or performing other activities, or performing nothing at all, or performing only selected activities, and so on. In some embodiments non-compliance is permanent, while in others it is temporary and/or restorable.

Claims

1. An Integrated Circuit (IC) chip for use with a Radio Frequency Identification (RFID) tag having an antenna, comprising:

a processing block operable to;

receive a first command from an RFID reader via the antenna; and

comply with the first command by performing a first operation and adjust a counter to advance towards a limit, if the counter had not reached a limit by a prior such adjusting, else not comply with the first command by not performing the first operation.

2. The IC chip of claim 1, in which

the counter is adjusted by being decremented, and

the limit is zero.

3. The IC chip of claim 1, in which

the counter had reached the limit, and therefore the first operation is not performed, and

an Out_Of_Cycles reply to the first command is backscattered that indicates non-compliance.

4. The IC chip of claim 1, in which

the first command includes an attempted password, and

the counter is further adjusted if the attempted password is not valid.

5. The IC chip of claim 1, in which

the tag stores a first multi-bit password in a memory,

bits of an attempted password are received in association with the first command, the attempted password bits corresponding to respective bits of the first password for complying with the first command, and

the counter is adjusted by an amount in relation to how many of the attempted password bits differ from their corresponding bits of the first password.

6. The IC chip of claim 1, in which

the limit had not been reached, and therefore the first command is complied with, and

two more commands are then received,

both are complied with, but

the counter is adjusted by different amounts for each of them.

7. The IC chip of claim 1, in which

not complying with the first command includes no longer performing the first operation responsive to subsequently received commands.

8. The IC chip of claim 1, in which

the limit had been reached, and therefore the first command is not complied with, and

then a second command is received, and is not complied with.

9. The IC chip of claim 8, in which

when the second command is received the tag has been killed.

10. The IC chip of claim 8, in which

then a third command is then received, and is complied with.

11. The IC chip of claim 1, in which

the counter becomes reset to an updated value.

12. The IC chip of claim 1, in which

the updated value is determined at random.

13. The IC chip of claim 1, in which

the updated value is determined from a preset initial value stored in tag memory.

14. The IC chip of claim 11, in which

the limit had been reached, and therefore the first command is not complied with, and

a Restore command is then received, and then a subsequently received command is complied with by performing the first operation.

15. The IC chip of claim 14, in which

the subsequently received command is complied with only if the Restore command encodes a valid restore password.

16. The IC chip of claim 14, in which

the updated value is determined from the Restore command.

17. The IC chip of claim 11, in which

the counter is reset responsive to receiving a Reset command.

18. The IC chip of claim 17, in which

the updated value is determined from the Reset command.

19. The IC chip of claim 17, in which

the Reset command is made from the Select command of FIG. 12A of this document, which further has a reset payload, and

the counter is reset responsive to the reset payload.

20. The IC chip of claim 1, in which

the first command is an Inquire command, and

the limit had not been reached, and

the Inquire command is complied with, by backscattering a reply indicating a state of the counter with respect to the limit.

21. The IC chip of claim 1, in which

the first command has been complied with,

a Disable command is received after the first command, and

a command received after the Disable command is complied with by performing the first operation, regardless of whether or not the counter reaches the limit.

22. The IC chip of claim 21, in which

the Disable command is made from the Select command of FIG. 12A of this document, which further has a disable payload, and

the command received after the Disable command is complied with responsive to the disable payload.

23. The IC chip of claim 1, in which

an Enable command is received prior to receiving the first command, and

a command received prior to the Enable command has been complied with by performing the first operation, regardless of whether or not the counter had reached the limit.

24. A Radio Frequency Identification (RFID) tag, comprising:

an antenna; and

a circuit coupled to the antenna, the circuit including a processing block operable to

receive a first command from an RFID reader; and

comply with the first command by performing a first operation and adjust a counter to advance towards a limit, if the counter had not reached the limit by a prior such adjusting, else not comply with the first command by not performing the first operation.

25. A method for a Radio Frequency Identification (RFID) tag, comprising:

receiving a first command from an RFID reader; and

complying with the first command by performing a first operation and adjusting a counter to advance towards a limit, if the counter had not reached the limit by a prior such adjusting, else not complying with the first command by not performing the first operation.