RFID system and RFID chip equipped with sensor function

• US 7,688,182 B2
• Filed: 02/24/2006
• Issued: 03/30/2010
• Est. Priority Date: 10/31/2005
• Status: Expired due to Fees

• Current Assignee: Fujitsu Semiconductor Memory Solution Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Microelectronics Limited (Fujitsu Limited)
• Inventors: Nagai, Eiichi
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): GIRMA, FEKADESELASS
• Application Number:
  US11/360,601
• Publication Number:
  US 20070096880A1
• Time in Patent Office: 1,495 Days
• Field of Search: 340/10.34
• US Class Current: 340/10.41
• CPC Class Codes: G06K 19/0717 the sensor being capable of sensing environmental conditions such as temperature history or pressure
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs

Abstract

An integrated circuit chip includes a rectifier circuit configured to convert an alternating voltage supplied from an antenna into a direct-current voltage, a nonvolatile memory coupled to the rectifier circuit to operate by use of the direct-current voltage, a sensor circuit coupled to the rectifier circuit to operate by use of the direct-current voltage to collect measurement data, and a logic circuit configured to control the nonvolatile memory and the sensor circuit such that an access operation of the nonvolatile memory and a data collecting operation of the sensor circuit are not performed concurrently.

Claims

1. An integrated circuit chip, comprising:

a rectifier circuit configured to convert an alternating voltage supplied from an antenna into a first direct-current voltage;

a nonvolatile memory coupled to said rectifier circuit to operate by use of the first direct current voltage;

a sensor circuit coupled to said rectifier circuit to operate by use of the first direct-current voltage to collect measurement data;

a logic circuit configured to control said nonvolatile memory and said sensor circuit such that a write access operation of said nonvolatile memory and a data collecting operation of said sensor circuit are not performed concurrently; and

a data modulation circuit configured to modulate the measurement data,

wherein the write access operation of said nonvolatile memory is performed before the modulated measurement data is output via the antenna,

wherein the write access operates by use of a second direct-current voltage, and the second direct-current voltage is lower than the first direct-current voltage.

2. The integrated circuit chip as claimed in claim 1, wherein said logic circuit is configured to cause said sensor circuit to perform the data collecting operation in response to a predetermined command received via the antenna, and is configured to perform the write access operation to write measurement data obtained by the data collecting operation to said nonvolatile memory after the completion of the data collecting operation.

3. The integrated circuit chip as claimed in claim 2, wherein the measurement data stored in the register is transmitted to the data modulation circuit via the input/output circuit said logic circuit includes a register that temporarily stores the measurement data obtained by the data collecting operation.

4. The integrated circuit chip as claimed in claim 1, wherein an electric power consumed by said sensor circuit performing the data collecting operation is smaller than an electric power consumed by said nonvolatile memory performing the write access operation.

10. The integrated circuit chip as claimed in claim 1, further comprising:

a data demodulation circuit configured to demodulate a command signal supplied from the antenna; and

a control circuit configured to perform a write operation according to the demodulated command signal.

11. The integrated circuit chip as claimed in claim 1, wherein the logic circuit includes:

a input/output circuit configured to receive first data from the antenna;

a memory interface circuit configured to receive second data from the nonvolatile memory;

a sensor interface circuit configured to receive the measurement data from the sensor circuit; and

a register configured to store the first data, the second data and the measurement data temporarily.

5. An RFID system, comprising:

a reader writer configured to transmit/receive a radio wave; and

an IC tag configured to communicate with said reader writer through the radio wave,

wherein said IC tag includes;

an antenna;

a rectifier circuit coupled to said antenna to convert an alternating voltage of the radio wave received by said antenna into a first direct-current voltage;

a nonvolatile memory coupled to said rectifier circuit to operate by use of the first direct-current voltage;

a sensor circuit coupled to said rectifier circuit to operate by use of the first direct-current voltage to collect measurement data;

a logic circuit configured to control said nonvolatile memory and said sensor circuit such that write access operation of said nonvolatile memory and a data collecting operation of said sensor circuit are not performed concurrently; and

a data modulation circuit configured to modulate the measurement data,

wherein control is performed such that an write access operation of said nonvolatile memory and a data collecting operation of said sensor circuit are not performed concurrently,

wherein the write access operation of said nonvolatile memory is performed before the modulated measurement data is output via the antenna,

wherein the logic circuit operates by use of a second direct-current voltage, and the second direct-current voltage is lower than the first direct-current voltage.

6. The RFID system as claimed in claim 5, wherein said reader writer is configured to transmit a first predetermined command to said IC tag to cause said sensor circuit to perform the data collecting operation, and is configured to transmit a second predetermined command to said IC tag to cause the write access operation for writing measurement data obtained by the data collecting operation to said nonvolatile memory to be performed after the completion of the data collecting operation.

9. The RFID system as claimed in claim 5, wherein an electric power consumed by said sensor circuit performing the data collecting operation is smaller than an electric power consumed by said nonvolatile memory performing the access operation.

12. The RFID system as claimed in claim 5, wherein the logic circuit includes:

a input/output circuit configured to receive first data from the antenna;

a memory interface circuit configured to receive second data from the nonvolatile memory;

a sensor interface circuit configured to receive the measurement data from the sensor circuit; and

a register configured to store the first data, the second data and the measurement data temporarily.

7. An IC tag for transmitting/receiving a radio wave to/from a reader writer, comprising:

an antenna;

a rectifier circuit coupled to said antenna to convert an alternating voltage of the radio wave received by said antenna into a first direct-current voltage;

a nonvolatile memory coupled to said rectifier circuit to operate by use of the first direct-current voltage;

a sensor circuit coupled to said rectifier circuit to operate by use of the first direct-current voltage to collect measurement data;

a logic circuit configured to control said nonvolatile memory and said sensor circuit by use of a second direct-current voltage such that a write access operation of said nonvolatile memory and a data collecting operation of said sensor circuit are not performed concurrently, wherein the second direct-current voltage is lower than the first direct-current voltage; and

a data modulation circuit configured to modulate the measurement data,

wherein control is performed such that a write access operation of said nonvolatile memory and a data collecting operation of said sensor circuit are not performed concurrently,

wherein the write access operation of said nonvolatile memory is performed before the modulated measurement data is output via the antenna.

8. The IC tag as claimed in claim 7, further comprising a register that temporarily stores the measurement data obtained by the data collecting operation.

13. The IC tag as claimed in claim 7, wherein the logic circuit includes:

a input/output circuit configured to receive first data from the antenna;

a memory interface circuit configured to receive second data from the nonvolatile memory;

a sensor interface circuit configured to receive the measurement data from the sensor circuit; and

a register configured to store the first data, the second data and the measurement data temporarily.