SMART CARD READER
A card reader receives an indication that a device has been plugged into a socket of the card reader. Power is provided to the socket in accordance with a first type of device. An attempt to communicate with the device is made in accordance with a first type of device protocol. If the communication attempt is not successful, power is provided to the socket in accordance with a second type of device, and communications commence with the device in accordance with a second type of device protocol.
1 . A method comprising:
receiving an indication that a device has been plugged into a socket;
providing power to the socket in accordance with a first type of device;
attempting to communicate with the device in accordance with a first type of device protocol;
if the communication attempt is not successful, providing power to the socket in accordance with a second type of device; and
communicating with the device in accordance with a second type of device protocol without interrupting a host.
2 . The method of claim 1 wherein the host is notified once successful communication is established with either the first or second type of device.
3 . The method of claim 1 wherein the first type of device protocol utilizes a non-differential voltage and the second type of device protocol utilizes a differential voltage.
4 . The method of claim 3 wherein the first type of device protocol utilizes one of several voltages.
5 . The method of claim 3 wherein the second type of device protocol has a higher data transfer rate than the first type of device protocol.
6 . The method of claim 1 wherein receiving an indication that a device has been plugged into a socket comprises detecting that a presence pin in the socket has been shorted to ground or a predetermined voltage when a card is plugged into the socket.
7 . The method of claim 6 and further comprising generating an interrupt in response to the presence pin having been shorted to ground or a predetermined voltage.
8 . The method of claim 1 wherein attempting to communicate with the device in accordance with a first type of device protocol comprises generating a reset signal on a reset pin of the socket.
9 . The method of claim 8 and further comprising waiting for an ‘Answer To Reset’ (ATR) from a first type of device.
10 . A card reader comprising:
a physical interface having a card presence connector;
a logic interface coupled to the physical interface;
a regulator coupled to the logic interface;
a controller coupled to the regulator and to the card presence connector to determine whether a first type of card is coupled to the physical interface and if not, to determine whether a second type of card is coupled to the physical interface; and
a processor coupled to the controller to initiate the controller.
11 . The card reader of claim 10 wherein the card reader is coupled to a host and the host is notified once successful communication is established with either the first or second type of card.
12 . The card reader of claim 10 wherein the first type of card includes a protocol that utilizes a non-differential voltage and the second type of card includes a protocol that utilizes a differential voltage.
13 . The card reader of claim 12 wherein the second type of card protocol has a higher data transfer rate than the first type of card protocol.
14 . The card reader of claim 10 wherein the controller generates an interrupt in response to the card presence connector being activated.
15 . The card reader of claim 14 wherein the card presence connector is shorted to ground when a card is plugged into the physical interface.
16 . The card reader of claim 10 wherein the controller generates a reset signal on a reset pin of the physical interface to attempt to communicate with a plugged in card in accordance with a first type of card protocol.
17 . The card reader of claim 16 wherein in the controller waits for an ‘Answer To Reset’ (ATR) from a first type of card.
18 . A card reader comprising:
a physical interface having a card presence connector;
a first and a second logic interface coupled to the physical interface;
a power supply coupled to the first logic interface;
a regulator coupled to the second logic interface;
a first controller coupled to the power supply and a second controller coupled to the power supply and the regulator; and
a processor coupled to the first and second controllers and to the card presence connector to initiate the first controller to determine whether a first type of card is coupled to the physical interface and if not, to initiate the second controller to determine whether a second type of card is coupled to the physical interface.
19 . The card reader of claim 18 wherein the first type of card includes a protocol that utilizes a non-differential voltage and the second type of card includes a protocol that utilizes a differential voltage.
20 . The card reader of claim 18 wherein the processor generates an interrupt in response to the card presence connector being activated.