POWER NEGOTATION FOR SMALL RFID CARD
A memory card compatible RFID card includes a smartcard controller that receives power from a host device. The RFID card also includes a small inductive device capable of inductive coupling with an RFID reader. The small inductive device is small enough to fit in the form factor of a memory card. Commands may be sent to the RFID card to keep the RFID card powered.
1 . A method comprising periodically sending memory card write commands to a memory card compatible add-on slot for the purpose of maintaining uninterrupted power to the memory card slot.
2 . The method of claim 1 wherein the memory card write commands include a hidden command in a data field.
3 . The method of claim 1 wherein the memory card write commands include a unique data string to identify the memory card write command as having a hidden command.
4 . The method of claim 1 wherein periodically sending memory card write commands comprises populating the memory card write commands with hidden commands to be disregarded by a device in the memory card compatible add-on slot.
5 . The method of claim 1 wherein periodically sending memory card write commands to a memory card compatible add-on slot comprises sending the memory card write commands to one of: an SD slot, a mini-SD slot, or a micro-SD slot.
6 . A method comprising:
embedding a hidden command within a memory card write command, the hidden command to specify a modification of power delivery to a dual interface smartcard controller on a memory card compatible radio frequency identification (RFID) card; and
sending the memory card write command to the memory card compatible RFID card.
7 . The method of claim 6 wherein sending the memory card write command to the memory card compatible RFID card comprises sending the memory card command to a memory card slot.
8 . The method of claim 7 wherein sending the memory card command to the memory card slot comprises sending the memory card command to one of: an SD slot, a mini SD slot, or a micro SD slot.
9 . The method of claim 6 wherein embedding a hidden command within a memory card write command comprises including a data string within the memory card write command to identify the memory card write command as a hidden command.
10 . A method comprising:
receiving a command at a memory card controller, wherein the command includes an instruction to modify power delivery to a dual interface smartcard controller co-located with the memory card controller on a memory card; and
modifying the power delivery to the dual interface smartcard controller.
11 . The method of claim 10 wherein modifying power delivery to the dual interface smartcard controller comprises removing power from the dual interface smartcard controller.
12 . The method of claim 10 wherein modifying power delivery to the dual interface smartcard controller comprises applying power to the dual interface smartcard controller.
13 . The method of claim 10 wherein receiving a command at a memory card controller comprises receiving a memory card write command from a host device to which the memory card is connected.
14 . The method of claim 10 wherein receiving a command at a memory card controller comprises receiving a hidden command in a memory card write command.
15 . The method of claim 10 further comprising receiving a second command at the memory card controller, wherein the second command includes an instruction to reset the dual interface smartcard controller.
16 . A computer-readable medium encoded with instructions that when accessed by a memory card controller result in the memory card controller performing:
receiving a command at the memory card controller, wherein the command includes an instruction to modify power delivery to a dual interface smartcard controller co-located with the memory card controller on a memory card; and
modifying power delivery to the dual interface smartcard controller.
17 . The computer-readable medium of claim 16 wherein modifying power delivery to the dual interface smartcard controller comprises cycling power to the dual interface smartcard controller.
18 . The computer-readable medium of claim 16 wherein receiving a command at the memory card controller comprises receiving a memory card write command from a host device to which the memory card is connected.
19 . The computer-readable medium of claim 16 wherein receiving a command at the memory card controller comprises receiving a hidden command in a memory card write command.