Host for use with dual interface card with backward and forward compatibility
View Patent ↗Techniques are presented that allow a memory card operable according to two protocols (such as a legacy protocol and newer protocol), and having a corresponding dual interface, to be used with hosts that support the new protocol as well as having backward compatibility with legacy hosts, while preventing the use of legacy cards with hosts that support the new protocol but do not support the legacy protocol. The card that supports the new protocol has a similar form factor to the legacy card, includes an indentation. A host that supports the new, but not the legacy, type card includes a mechanical structure within the attachment slot that, based on the card indentation, can distinguish the card types and prevent the non-supported card from being attached.
1. A digital appliance comprising:
a slot structure having a slot opening to allow a first type memory card having a first set of contacts to be removably connected by insertion into the slot structure,
the slot structure having formed therein a mechanical structure including:
a pivot structure, and
a lever arm configured to pivot on the pivot structure, wherein a portion of the lever arm is configured to at least partially fit into an indentation of the first type memory card to distinguish the first type memory card from a second type memory card,
the second type memory card having a second set of contacts, where the first and second sets of contacts differ by at least one of the contacts, and
the first and second type memory cards having a similar form factor except for the indentation along a first edge of the first type memory card, the first edge being other than a second edge of the first type memory card inserted into the digital appliance when the memory card is inserted into the slot for connection thereto, the first and second edges defining an angle therebetween, whereby the mechanical structure prevents the connection of the second type memory based on the lack of the indentation.
2. The digital appliance of claim 1 , wherein the first edge is orthogonal to the second edge.
3. The digital appliance of claim 1 , wherein the slot is rectangular or of another form that fits the physical shape of the memory card.
4. The digital appliance of claim 1 , wherein the first type memory card also has the second set of contacts.
5. The digital appliance of claim 1 , wherein the second type memory card operates according to a micro secure digital (SD) card protocol.
6. The digital appliance of claim 1 , where the first and second sets of contacts are distinct.
7. The digital appliance of claim 1 , where the first and second sets of contacts share one or more contacts.
8. The digital appliance of claim 1 , where one of the first and second sets of contacts is a subset of the other of the first and second sets of contacts.
9. The digital appliance of claim 1 , wherein the form factor has the physical margins of a micro SD card.
10. The digital appliance of claim 1 , wherein the form factor has the physical margins of an SD card.