IC tag, method of controlling the IC tag, and IC tag system

• US 8,174,365 B2
• Filed: 09/26/2006
• Issued: 05/08/2012
• Est. Priority Date: 09/27/2005
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Akiyama, Kazuhiro, Igarashi, Hatsuhide, Okamoto, Seiichi, Miyashita, Toshiyuki, Seki, Kazumi, Uchino, Tatsuya
• Primary Examiner(s): Syed, Nabil
• Application Number:
  US11/526,626
• Publication Number:
  US 20070069863A1
• Time in Patent Office: 2,051 Days
• Field of Search: 340/10.2, 340/10.3, 340/10.4, 340/10.51, 340/572.1, 235/492
• US Class Current: 340/10.2
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

To provide an IC tag, a method of controlling the IC tag, and an IC tag system which can reduce a communication sequence between the reader/writer and the IC tag and can shorten a communication period or a period necessary for executing the command. According to an embodiment of the invention, an IC tag that executes a command processing based on a command received from a redder/writer, includes: a command analyzing unit determining an execution condition of the command received from the redder/writer; and a command execution unit executing a first command processing if the execution condition is met, and executing a second command processing different from the first command processing if the execution condition is not met.

Claims

1. A method of identifying tags in a communication area through an anti-collision by a reader/writer, the tags including first and second tags in the communication area, the first tag including a first memory storing a first tag ID and a first sleep flag, the second tag including a second memory storing a second tag ID and a second sleep flag, the first tag ID being different from the second tag ID, the method comprising:

transmitting a first WAKE command from the reader/writer;

setting, in response to the first WAKE command, a first value to the first sleep flag, the first value of the first sleep flag being indicative of a permission of a transmission of the first tag ID;

setting, in response to the first WAKE command, a first value to the second sleep flag, the first value of the second sleep flag being indicative of a permission of a transmission of the second tag ID;

transmitting a first tag ID read command from the reader/writer after the setting of the first value to the first sleep flag and of the first value to the second sleep flag in response to the first WAKE command;

transmitting, in response to the first tag ID read command, the first tag ID from the first tag and the second tag ID from the second tag;

detecting a collision of the received first and second tag IDs to transmit a tag ID read/SLEEP command from the reader/writer, the tag ID read/SLEEP command including a first tag ID range as a condition, the first tag ID range including the second tag ID but not including the first tag ID;

receiving the tag ID read/SLEEP command at the first tag to transmit the first tag ID from the first tag;

receiving the tag ID read/SLEEP command at the second tag to set a second value to the second sleep flag, the second value of the second sleep flag being indicative of a prohibition of the transmission of the second tag ID; and

receiving, at the reader/writer, the first tag ID transmitted corresponding to the tag ID read/SLEEP command to identify the first tag in the communication area.

2. The method according to claim 1, wherein the first memory stores a first isolate flag, the second memory stores a second isolate flag, the method further comprises:

transmitting a RESET command from the reader/writer before the transmitting of the first WAKE command;

setting, in response to the RESET command, a first value to the first isolate flag, the first value of the first isolate flag being indicating that the first tag is not identified by the reader/writer;

setting, in response to the RESET command, a second value to the second isolate flag, the first value of the second isolate flag being indicating that the second tag is not identified by the reader/writer;

transmitting an ISOLATE command from the reader/writer after the receiving of the first tag ID transmitted corresponding to the tag ID read/SLEEP command; and

setting, in response to the ISOLATE command, a second value to the first isolate flag, the second value of the first isolate flag being indicating that the first tag is identified by the reader/writer.

3. The method according to claim 2, further comprising:

transmitting a second WAKE command from the reader/writer after the setting of the second value to the first isolate flag in response to the ISOLATE command;

setting, in response to the second WAKE command, the first value to the second sleep flag;

transmitting a SLEEP command from the reader/writer after the setting of the first value to the second sleep flag in response to the WAKE command, the SLEEP command including a condition that each of the first and second isolate flags is equal to the second value;

setting, in response to the SLEEP command, a second value to the first sleep flag, the second value of the first sleep flag being indicative of a prohibition of the transmission of the first tag ID;

transmitting a second tag ID read command from the reader/writer after the setting of the second value to the first sleep flag in response to the SLEEP command;

transmitting, in response to the second tag ID read command, the second tag ID from the second tag;

receiving, at the reader/writer, the second tag ID transmitted corresponding to the second tag ID read command to identify the second tag in the communication area;

transmitting an ISOLATE command from the reader/writer after the receiving of the second tag ID transmitted corresponding to the second tag ID read command; and

setting, in response to the ISOLATE command, a second value to the second isolate flag, the second value of the second isolate flag being indicating that the second tag is identified by the reader/writer.

4. The method according to claim 1, wherein the first memory stores a first isolate flag, the second memory stores a second isolate flag, the method further comprises:

transmitting a RESET command from the reader/writer before the transmitting of the first WAKE command;

setting, in response to the RESET command, a first value to the first isolate flag, the first value of the first isolate flag being indicating that the first tag is not identified by the reader/writer;

setting, in response to the RESET command, a second value to the second isolate flag, the first value of the second isolate flag being indicating that the second tag is not identified by the reader/writer;

transmitting an ISOLATE/WAKE command from the reader/writer after the receiving of the first tag ID transmitted corresponding to the tag ID read/SLEEP command;

setting, in response to the ISOLATE/WAKE command, a second value to the first isolate flag, the second value of the first isolate flag being indicating that the first tag is identified by the reader/writer; and

setting, in response to the ISOLATE/WAKE command, the first value to the second sleep flag.

5. The method according to claim 4, further comprising:

transmitting a SLEEP command from the reader/writer after the setting of the second value to the first isolate flag and of the first value to the second sleep flag in response to the ISOLATE/WAKE command, the SLEEP command including a condition that each of the first and second isolate flags is equal to the second value;

setting, in response to the SLEEP command, a second value to the first sleep flag, the second value of the first sleep flag being indicative of a prohibition of the transmission of the first tag ID;

transmitting a second tag ID read command from the reader/writer after the setting of the second value to the first sleep flag in response to the SLEEP command;

transmitting, in response to the second tag ID read command, the second tag ID from the second tag;

receiving, at the reader/writer, the second tag ID transmitted corresponding to the second tag ID read command to identify the second tag in the communication area;

transmitting an ISOLATE command from the reader/writer after the receiving of the second tag ID transmitted corresponding to the second tag ID read command; and

setting, in response to the ISOLATE command, a second value to the second isolate flag, the second value of the second isolate flag being indicating that the second tag is identified by the reader/writer.

6. The method according to claim 2, further comprising:

transmitting a second WAKE command from the reader/writer after the setting of the second value to the first isolate flag in response to the ISOLATE command;

setting, in response to the second WAKE command, the first value to the second sleep flag;

transmitting a tag ID read/write command from the reader/writer after the setting of the first value to the second sleep flag in response to the second WAKE command, the tag ID read /write command including a second tag ID range as a condition, the second tag ID range including the first tag ID but not including the second tag ID;

executing, in response to the tag ID read/write command, a write processing at the first tag to transmit a message indicating that the write processing is completed from the first tag;

transmitting, in response to the tag ID read/write command, the second tag ID from the second tag; and

receiving, at the reader/writer, the second tag ID transmitted corresponding to the tag ID read/write command to identify the second tag in the communication area.

7. The method according to claim 6,

wherein a timing of the transmitting of the message from the first tag is different from a timing of the transmitting of the second tag ID from the second tag.

8. The method according to claim 1,

wherein the first and second sleep flags are indicative of communication states of the first and second tags,

wherein the communication state of the first tag is not changed in response to the tag ID read/SLEEP command from the reader/writer, and

wherein the communication state of the second tag is changed in response to the tag ID read/SLEEP command from the reader/writer.

9. A method of identifying tags in a communication area through an anti-collision by a reader/writer, the tags including first and second tags in the communication area, the first tag including a first memory storing a first tag ID and a first sleep flag, the second tag including a second memory storing a second tag ID and a second sleep flag, the first tag ID being different from the second tag ID, the method comprising:

transmitting a WAKE command from the reader/writer;

setting, in response to the WAKE command, a first value to the first sleep flag, the first value of the first sleep flag being indicative of a permission of a transmission of the first tag ID;

setting, in response to the WAKE command, a first value to the second sleep flag, the first value of the second sleep flag being indicative of a permission of a transmission of the second tag ID;

transmitting a tag ID read command from the reader/writer after the setting of the first value to the first sleep flag and of the first value to the second sleep flag in response to the WAKE command;

transmitting, in response to the tag ID read command, the first tag ID from the first tag and the second tag ID from the second tag;

detecting a collision of the received first and second tag IDs to transmit a tag ID read/SLEEP command from the reader/writer, the tag ID read/SLEEP command including an ID information as a condition, the ID information including the second tag ID but not including the first tag ID;

comparing the ID information with the first and second tag IDs to determine which of the first or second tags is corresponding to the condition;

transmitting the first tag ID to the reader/writer based on a result of the comparing;

setting a second value to the second sleep flag to prohibit a transmission the second tag ID; and

identifying the first tag in the communication area based on a result of the transmitting of the first tag ID.

10. The method according to claim 9,

wherein the first and second sleep flags are indicative of communication states of the first and second tags,

wherein the communication state of the first tag is not changed in response to the tag ID read/SLEEP command from the reader/writer, and

wherein the communication state of the second tag is changed in response to the tag ID read/SLEEP command from the reader/writer.

11. The method according to claim 9,

wherein the second tag does not execute a processing of transmitting data to the reader/writer in response to the tag ID read/SLEEP command, and

wherein the first tag executes the processing in response to the tag ID read/SLEEP command.