Random code for device identification

• US 6,888,898 B1
• Filed: 05/25/2000
• Issued: 05/03/2005
• Est. Priority Date: 05/25/2000
• Status: Expired due to Term

• Current Assignee: Logitech Europe S A (Logitech International SA)
• Original Assignee: Logitech Europe S A (Logitech International SA)
• Inventors: Chênes, Pierre H.
• Primary Examiner(s): Fan, Chieh M.
• Assistant Examiner(s): Perilla, Jason M.
• Application Number:
  US09/580,932
• Time in Patent Office: 1,804 Days
• Field of Search: 708/250, 327/100, 331/78, 375/130, 375/146, 375/147, 375/219, 375295-315, 375316-352, 341/22, 340/825.54
• US Class Current: 375/295
• CPC Class Codes: G06F 3/0231 Cordless keyboards
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 61/5038 for local use, e.g. in LAN or USB networks, or in a controller area network [CAN]
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A random identifier code is generated. The random identifier code is for allowing an electrical circuit to be communicatively associated with a particular external entity. The generated random identifier code is derived from signal data produced by the circuit. In the context of a wireless communication system, a transmitter and receiver can be associated with one another by such a random identifier code. Transmissions of the transmitter can be identified based on the random identifier code. No additional memory module needs to be installed during the manufacturing process for storing a predefined code. Once a random code identifier is generated, the associated circuit-external entity pair (e.g., transmitter-receiver pair) can continue to use that code indefinitely. However, a new code can be generated at any given time if so desired.

Claims

1. A wireless communications system comprising:

a transmitter circuit for transmitting information and configured to generate a random identifier code having randomness that is derived from manufacturing tolerances associated with components included in the transmitter circuit, wherein the random identifier code is included in the transmitted information, the generation of the random identifier code being configured to repeatedly obtain a same result,

wherein the transmitter circuit includes a microcontroller unit having a first input/output (I/O) port, wherein in response to detecting an event responsive to the manufacturing tolerances being detected at the first I/O port, a process running in the microcontroller unit generates the random identifier code.

2. The system of claim 1 wherein the microcontroller unit includes a read only memory (ROM) for storing a set of instructions for carrying out the process.

3. The system of claim 1 wherein the microcontroller unit includes a random access memory (RAM) for storing the random identifier code generated by the process.

4. The system of claim 1 wherein the microcontroller unit includes a N-bit timer having an output value that is read in response to the code generating event being detected at the first I/O port.

5. The system of claim 4 wherein the output value of the N-bit timer is the random identifier code.

6. The system of claim 4 wherein the output value of the N-bit timer is applied to a random code generator algorithm stored in a read only memory (ROM) of the microcontroller unit, the random code generator algorithm for generating the random identifier code.

7. The system of claim 1 wherein the transmitter circuit further includes a storage area for storing the random identifier code.

8. The system of claim 1 wherein the transmitter circuit is included in one of a wireless mouse, a wireless keyboard, a wireless joystick, a wireless trackball, a wireless video camera and a receiver unit for receiving communications of a wireless device.

9. A wireless communications system comprising:

a transceiver circuit for transmitting information, and for generating a random identifier code having randomness that is derived from manufacturing tolerances associated with components included in the transceiver circuit, wherein the random identifier code is included in the transmitted information, the generation of the random identifier code being configured to repeatedly obtain a same result,

wherein the transceiver circuit includes a microcontroller unit having a first input/output (I/O) port, wherein in response to detecting an event responsive to the manufacturing tolerances being detected at the first I/O port, a process running in the microcontroller unit generates the random identifier code.

10. The system of claim 9 wherein the microcontroller unit includes a read only memory (ROM) for storing a set of instructions for carrying out the process.

11. The system of claim 9 wherein the microcontroller unit includes a random access memory (RAM) for storing the random identifier code generated by the process.

12. The system of claim 9 wherein the microcontroller unit includes an N-bit timer having an output value that is read in response to the event being detected at the first I/O port.

13. The system of claim 12 wherein the output value of the N-bit timer is the random identifier code.

14. The system of claim 12 wherein the output value of the N-bit timer is applied to a random code generator algorithm stored in a read only memory (ROM) of the microcontroller unit, the random code generator algorithm for generating the random identifier code.

15. The system of claim 9 wherein the transceiver circuit further includes a storage area for storing the random identifier code.

16. The system of claim 9 wherein the transceiver circuit is included in one of a wireless mouse, a wireless keyboard, a wireless joystick, a wireless trackball, a wireless video camera and a receiver unit for receiving communications of a wireless device.

17. A method for distinguishing transmissions of a wireless transmitter, the method comprising:

generating a random identifier code having randomness that is derived from manufacturing tolerances associated with components included in the wireless transmitter, the generation of the random identifier code being configured to repeatedly obtain a same result; and

embedding the random identifier code in the transmissions of the wireless transmitter,

wherein the wireless transmitter includes a microcontroller unit having an input/output (I/O) port, and the generating step is in response to an event responsive to the manufacturing tolerances being detected at the I/O port.

18. The method of claim 17 further comprising:

storing the random identifier code in a storage area in the wireless transmitter.

19. The method of claim 17 wherein the microcontroller unit includes a read only memory (ROM) for storing a set of instructions, and the generating step is carried out pursuant to the instructions.

20. The method of claim 17 wherein the wireless transmitter is included in one of a wireless mouse, a wireless keyboard, a wireless joystick, a wireless trackball, a wireless video camera and a receiver unit for receiving communications of a wireless device.

21. A method for distinguishing transmissions of a transceiver included in a wireless communications system, the method comprising:

generating a random identifier code having randomness that is derived from manufacturing tolerances associated with components included in the transceiver; and

embedding the random identifier code in the transmissions of the transceiver, the generation of the random identifier code being configured to repeatedly obtain a same result,

wherein the wireless transmitter includes a microcontroller unit having an input/output (I/O) port, and the generating step is in response to an event responsive to the manufacturing tolerances being detected at the I/O port.

22. The method of claim 21 further comprising:

storing the random identifier code in a storage area in the wireless transmitter.

23. The method of claim 21 wherein the microcontroller unit includes a read only memory (ROM) for storing a set of instructions, and the generating step is carried out pursuant to the instructions.

24. The method of claim 21 wherein the transceiver is included in one of a wireless mouse, a wireless keyboard, a wireless joystick, a wireless trackball, a wireless video camera and a receiver unit for receiving communications of a wireless device.

25. A computer-readable medium having instructions stored thereon which, when executed by a processor included in a wireless communications system, when executed by a processor included in a wireless communications system, cause the processor to perform the steps of:

in response to an event responsive to manufacturing tolerances associated with components included in the communications system, receiving data produced by the wireless communications system, wherein the received data has randomness that is derived from the manufacturing tolerances associated with the components included in the wireless communications system;

generating a random identifier code based on the received data; and

storing the random identifier code in a storage area included in the wireless communications system, the generation of the random identifier code being configured to repeatedly obtain a same result.

26. The computer-readable medium of claim 25, wherein the steps performed by the processor further comprise:

embedding the random identifier code in transmissions of the wireless communications system.

27. The computer-readable medium of claim 25 wherein the wireless communications system includes a microcontroller unit having an I/O port, and the event is detected at the I/O port.

28. A method for distinguishing transmissions of a wireless communications device, wherein the wireless communications device has a microcontroller unit having an input/output (I/O) port coupled to a resistor capacitive (RC) circuit having an output voltage that can be monitored by the I/O port, the method comprising:

responsive to a triggering event, commanding the I/O port of the microcontroller unit from a high impedance state to a low voltage state thereby discharging the RC circuit;

resetting and starting an N-bit timer of the microcontroller unit, the N-bit timer having an output;

commanding the I/O port from the low voltage state to the high impedance state thereby charging the RC circuit;

monitoring the output voltage of the RC circuit at the I/O port;

responsive to the output voltage at the I/O port reaching a threshold voltage, reading the output of the N-bit timer;

generating from the read output of the N-bit timer a random identifier code; and

embedding the random identifier code in transmissions of the wireless communications device.