Memory cards including a standard security function
A memory card of one published standard, such as the Multi-Media Card (MMC) or Secure Digital Card (SD), is modified to include the function of a Subscriber Identity Module (SIM) according to another published standard. The controller of the memory card communicates between electrical contacts on the outside of the card and both the memory and the SIM. In one specific form, the memory card has the physical configuration of the current Plug-in SIM card with a few external contacts added to accommodate the memory controller and data memory. In another specific form, the memory card has the physical configuration of the current SD card, including external contacts.
1. A storage device comprising:
a set of electrical contacts;
a memory; and
a controller in communication with the electrical contacts and the memory, wherein the controller is configured to operate in either a first operating mode or a second operating mode, wherein the controller executes commands received through the electrical contacts differently depending on whether the controller is operating in the first operating mode or the second operating mode, and wherein controller is further configured to:
receive a command through the electrical contacts that causes the controller to switch from the first operating mode to the second operating mode; and
execute subsequently-received commands received through the electrical contacts according to the second operating mode until a command is received through the electrical contacts that causes the controller to switch from the second operating mode to the first operating mode.
2. The storage device of claim 1 further comprising a Subscriber Identify Module (SIM) in communication with the controller, wherein the controller executes commands with respect to the memory when in the first operating mode, and wherein the controller executes commands with respect to the SIM when in the second operating mode.
3. The storage device of claim 1 , wherein the first operating mode operates according to one of the following protocols: the Secure Digital (SD) protocol, the MultiMedia Card (MMC) protocol, and the Memory Stick protocol.
4. The storage device of claim 1 , wherein the commands that cause the controller to switch between the first and second operating modes are application-specific commands.
5. The storage device of claim 4 , wherein the application-specific commands are part of the MultiMedia Card (MMC) protocol.
6. The storage device of claim 1 , wherein the controller includes:
a first plurality of lines for use when the controller is operating in the first operating mode;
a second plurality of lines for use when the controller is operating in the second operating mode; and
host interface circuitry connected to the external contacts, wherein the host interface circuitry has a switching circuit connected with at least some of the first and second plurality of lines;
wherein, in the first operating mode, the host interface circuitry connects at least some of the first plurality of lines to specified ones of the external contacts while maintaining the second plurality of lines disconnected therefrom; and
wherein, in the second operating mode, the host interface circuitry connects said at least some of the second plurality of lines to said specified ones of the external contacts while maintaining the first plurality of lines disconnected therefrom.
7. A method for executing commands in a storage device, the method comprising:
performing the following in a storage device comprising a set of electrical contacts, a memory, and a controller in communication with the electrical contacts and the memory, wherein the controller is configured to operate in either a first operating mode or a second operating mode, wherein the controller executes commands received through the electrical contacts differently depending on whether the controller is operating in the first operating mode or the second operating mode:
receiving a command through the electrical contacts that causes the controller to switch from the first operating mode to the second operating mode; and
executing subsequently-received commands received through the electrical contacts according to the second operating mode until a command is received through the electrical contacts that causes the controller to switch from the second operating mode to the first operating mode.
8. The method of claim 7 , wherein the storage device comprises a Subscriber Identify Module (SIM) in communication with the controller, and wherein the method further comprises executing commands with respect to the memory when in the first operating mode, and wherein the controller executes commands with respect to the SIM when in the second operating mode.
9. The method of claim 7 , wherein the first operating mode operates according to one of the following protocols: the Secure Digital (SD) protocol, the MultiMedia Card (MMC) protocol, and the Memory Stick protocol.
10. The method of claim 7 , wherein the commands that cause the controller to switch between the first and second operating modes are application-specific commands.
11. The method of claim 10 , wherein the application-specific commands are part of the MultiMedia Card (MMC) protocol.
12. The method of claim 7 , wherein the controller includes:
a first plurality of lines for use when the controller is operating in the first operating mode;
a second plurality of lines for use when the controller is operating in the second operating mode; and
host interface circuitry connected to the external contacts, wherein the host interface circuitry has a switching circuit connected with at least some of the first and second plurality of lines;
wherein, in the first operating mode, the host interface circuitry connects at least some of the first plurality of lines to specified ones of the external contacts while maintaining the second plurality of lines disconnected therefrom; and
wherein, in the second operating mode, the host interface circuitry connects said at least some of the second plurality of lines to said specified ones of the external contacts while maintaining the first plurality of lines disconnected therefrom.