Dual interface card with backward and forward compatibility

1. A memory card comprising:

a first set of contacts, a first edge, a second edge that includes an indentation, and a second set of contacts configured to be engaged with a host device in response to insertion of at least a portion of a third edge of the memory card into a cavity of the host device, wherein:

the first edge is configured to be inserted into the cavity,

the indentation is configured to accept a first end of a pivoting lever arm within the cavity upon insertion of the first edge into the cavity such that a second end of the pivoting lever arm moves away from all of the first edge to contact the second edge, and

the first set of contacts is configured to be engaged with the host device in response to acceptance by the indention of the first end of the pivoting lever arm.

2. The memory card of claim 1 , wherein movement of the second end of the pivoting lever arm away from the first edge enables engagement of the first set of contacts with the host device.

3. The memory card of claim 1 , wherein the first edge and the second edge are oriented approximately orthogonally with respect to one another, and further comprising a second indentation in at least one of the first edge and the third edge.

4. The memory card of claim 1 , further comprising a controller configured to:

communicate with the host device using a first protocol while operatively coupled to the host device via the first set of contacts; and

communicate with the host device using a second protocol while operatively coupled to the host device via the second set of contacts.

5. The memory card of claim 1 , wherein the second edge is configured to interact with the first end of the pivoting lever arm to cause the second end of the pivoting lever arm to:

allow insertion of the memory card into the cavity by not blocking a portion of the cavity in response to the first end of the pivoting lever arm contacting the indentation; and

disallow insertion of the memory card into the cavity by blocking the portion of the cavity in response to the first end of the pivoting lever arm not contacting the indentation.

6. The memory card of claim 1 , wherein a form factor of the memory card is configured to allow for connection to the host device while the host device supports a first protocol through use of the first set of contacts and does not support a second protocol through use of the second set of contacts.

7. The memory card of claim 6 , wherein the form factor is one of a secure digital card form factor or a micro secure digital card form factor.

8. The memory card of claim 1 , wherein the first set of contacts shares at least one contact with the second set of contacts.

9. The memory card of claim 1 , wherein:

an entirety of the pivoting lever arm is located in the cavity, and

an entirety of the memory card is positioned in the cavity while the first set of contacts is electrically coupled to an interface of the host device.

10. The memory card of claim 1 , wherein the indentation is further configured to, in response to insertion of the first edge into the cavity, enable the host device to distinguish the memory card from another type of memory card based on a position of the pivoting lever arm.

11. The memory card of claim 1 , wherein the indentation is located at a distance from the first edge and is further configured to cause the second end of the pivoting lever arm to, during insertion of the first edge, move away from the first edge to enable engagement of the first set of contacts.

12. A method comprising:

in a memory card having a first set of contacts, a first edge that includes an indentation, and a second set of contacts configured to be engaged with a host device in response to insertion of at least a portion of a third edge of the memory card into a cavity of the host device, performing, upon insertion of the memory card into the cavity:

accepting, at the indentation, a first end of a pivoting lever arm located in the cavity, the first end of the pivoting lever arm accepted at the indentation upon insertion of the memory card into the cavity such that a second end of the pivoting lever arm moves away from all of a second edge of the memory card to contact the first edge; and

engaging the first set of contacts to allow communication with the host device via the first set of contacts.

13. The method of claim 12 , wherein accepting the first end of the pivoting lever arm at the indentation indicates that the memory card supports communication via the first set of contacts.

14. The method of claim 12 , wherein:

the pivoting lever arm is included in an edge indentation detector of the host device, and

the indentation is mechanically engaged by the edge indentation detector in response to insertion of the memory card into the cavity.

15. The method of claim 12 , wherein accepting the first end of the pivoting lever arm causes the pivoting lever arm to move from a first location blocking engagement of the first set of contacts with an interface of the host device to a second location allowing engagement of the first set of contacts with the interface.

16. An electronic circuit card comprising:

means for interfacing with a host device;

first means for connecting the means for interfacing to the host device;

second means for connecting the means for interfacing to the host device, the second means for connecting configured to be engaged with the host device in response to insertion of at least a portion of third means for contacting of the electronic circuit card into a cavity of the host device; and

means for engaging configured to, when inserted into the cavity, engage a first end of a pivoting lever arm in the cavity causing a second end of the pivoting lever arm to:

move away from all of first means for contacting of the electronic circuit card,

contact an indentation in second means for contacting of the electronic circuit card, and

enable engagement of the first means for connecting with the host device.

17. The electronic circuit card of claim 16 , further comprising means for storing data and means for controlling the means for storing data, wherein:

the first means for contacting includes a first edge of the electronic circuit card,

the second means for contacting includes a second edge of the electronic circuit card,

the indentation is located on the second edge, and

the first edge is approximately orthogonal to the second edge.

18. The electronic circuit card of claim 16 , wherein the means for interfacing is configured to communicate with the host device using a first protocol in response to being operatively coupled to the host device via the first means for connecting and a second protocol in response to being operatively coupled to the host device via the second means for connecting.