Communication card with three operational states

A method for determining the operational state of a communication card, comprising:

• providing a communication card that has three operational states, namely, (i) the communication card in a standalone mode (State I), (ii) the communication card connected to a shell (State II), and (iii) the communication card connected to a host (State III);
• monitoring a first signal on the communication card;
• and
• if the first signal has a voltage level lower than a first designated threshold, then concluding that the communication card is in State I;
• otherwise, concluding that the communication card is connected to a device, and:
• monitoring a second signal on the communication card;
• and
• if the second signal has a voltage level lower than a second designated threshold, then concluding that the communication card is in State II;
• otherwise,
• concluding that the communication card is in State III.

A computer readable storage medium storing program code for causing a computing device to determine the state of a communication card that has three operational states, namely, (i) the communication card in a standalone mode (State I), (ii) the communication card connected to a shell (State II), and (iii) the communication card connected to a host (State III), by:

• monitoring a first signal on the communication card;
• and
• if the first signal has a voltage level lower than a designated threshold, then concluding that the communication card is in State I;
• otherwise, concluding that the communication card is connected to a device, and:
• monitoring a second signal on the communication card;
• and
• if the second signal has a voltage level lower than the designated threshold, then concluding that the communication card is in State II;
• otherwise,
• concluding that the communication card is in State III.

A communication card with three operational states, comprising:

• a card connector for connecting a communication card to a shell and to an electronic device, comprising:
• a connector for incoming and outgoing audio signals;
• a connector for a power supply;
• a universal serial bus (USB) connector;
• and
• a communication bus, wherein (i) no signals are routed to the communication bus when the card operates in a standalone mode (State I), (ii) secure digital (SD) card signals are routed to the communication bus when the card is connected to a shell (State II), with the card functioning as master, and (iii) SD card signals are routed to the communication bus when the card is connected to an electronic device (State III), with the card functioning as slave;
• and
• circuitry for automatically detecting whether the card is operating in State I, State II or State III.