INTERFACE ARBITRATION FOR A WIRED TAG

• US 20140062661A1
• Filed: 08/31/2012
• Published: 03/06/2014
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Gallo, Francesco, Bakker, Paul
• Granted Patent: US 9,514,067 B2
• Time in Patent Office: Days
• US Class Current: 340/9.1
• CPC Class Codes: G06F 13/1605 based on arbitration arbitration in handling access to a common bus or bus system G06F13/36
• CPC Class Codes: G06F 2213/0016 Inter-integrated circuit (I2C)
• CPC Class Codes: G06K 19/07769 the further communication means being a galvanic interface, e.g. hybrid or mixed smart cards having a contact and a non-contact interface

Abstract

Various exemplary embodiments relate to an integrated circuit (IC) including: a memory; a radio frequency (RF) interface configured to access the memory; a wired interface connected to a host and configured to access the memory; and an arbitration module configured to prevent concurrent access to the memory by more than one interface. Various exemplary embodiments relate to a method of controlling access in a dual interface tag having a wired interface and a radio frequency (RF) interface operable in an idle state, a wired lock state, and a RF locked state.

Claims

1. An integrated circuit (IC) comprising:

a memory;

a radio frequency (RF) interface configured to access the memory;

a wired interface connected to a host and configured to access the memory; and

an arbitration module configured to prevent concurrent access to the memory by more than one interface.

2. The IC of claim 1, further comprising a field detection (FD) pin that indicates whether an RF field is present.

3. The IC of claim 1, wherein the arbitration module comprises:

a first register configured to indicate the status of the RF interface and a second register configured to indicate the status of the wired interface.

4. The IC of claim 3, wherein the arbitration module is configured to block communication via the wired interface if the first register indicates that the RF interface is active and to block communication via the RF interface if the second register indicates that the wired interface is active.

5. The IC of claim 3, further comprising a field detection (FD) pin that indicates whether an RF field is present wherein the arbitration module is configured to set the first register when the FD pin indicates that an RF field is present.

6. The IC of claim 5, wherein the arbitration module waits until the second register indicates that the wired interface is inactive before blocking the wired interface.

7. The IC of claim 3, wherein the arbitration module is configured to reset the first register when the FD pin indicates that no RF field is present.

8. The IC of claim 3, wherein the arbitration module is configured to control the first register based on commands received via the RF interface.

9. The IC of claim 3, wherein the arbitration module is configured to control the second register based on an address received via the wired interface.

10. The IC of claim 3, wherein the arbitration module is configured to control the second register based on commands received via the wired interface.

11. The IC of claim 1, wherein the wired interface is an integrated inter-circuit (I²C) interface.

16. The method of claim 10, wherein the step of transitioning from an idle state to an RF locked state based on a status of the RF interface comprises setting a register associated with the RF interface based on the presence of a RF field.

12. A method of controlling access in a dual interface tag having a wired interface and a radio frequency (RF) interface operable in an idle state, a wired lock state, and a RF locked state, the method comprising:

transitioning from an idle state to a wired lock state based on a first communication received via the wired interface;

transitioning from a wired lock state to an idle state based on a second communication received via the wired interface or a lack of power on the wired interface;

transitioning from an idle state to an RF locked state based on a status of the RF interface; and

transitioning from an RF locked state to an idle state based on a status of the RF interface.

13. The method of claim 12 further comprising transitioning from a wired lock state to an RF locked state based on detection of an RF field.

14. The method of claim 12, wherein the status of the RF interface is based on the presence of an RF field.

15. The method of claim 12, wherein the status of the RF interface is based on commands received via the RF interface.

17. The method of claim 12, wherein the step of transitioning from an idle state to a wired lock state based on a first communication received via the wired interface comprises:

receiving an address via the wired interface;

determining that the address is a slave address of the tag on the wired interface; and

setting a register associated with the wired interface to indicate that the wired interface is busy.

18. The method of claim 12, wherein the step of transitioning from an RF locked state to an idle state based on a status of the RF interface comprises:

receiving a HALT message via the RF interface; and

resetting a register associated with the RF interface to indicate that the RF interface is not busy.