The foregoing and other features and advantages of the invention will be apparent from the more particular description of preferred aspects of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.
The connector 220 is to be connected with an external interface unit. The connector 220 includes eight contact pins C1˜C8. The contact pins C1˜C8 are grouped into first contact pins C4, C6, and C8, second contact pins C2, C3, and C7, and third contact pins C1 and C5.
The first contact pins, C4, C6, and C8, are provided to select one among different interface units 244, 246, and 248, excluding an ISO7816 interface unit 242. The contact pin C4 is connected to a pad P4 of the IC chip 240. The contact pin C4 is used for receiving data D+ from an external USB interface unit or inputting/outputting data MDATA from/to an external MMC interface unit. The contact pin C6 is connected to a pad P6 of the IC chip 240. The contact pin C6 is used for exchanging a signal SWP with an external SWP interface unit or receiving a clock MCLK from the external MMC interface unit. The contact pin C8 is connected to a pad C8 of the IC chip 240. The contact pin C8 is used for outputting data D− to the external USB interface unit or exchanging a command CMD with the external MMC interface unit.
The second contact pins, C2, C3, and C7, are provided for supplying signals only to the ISO7816 interface unit 242. Referring to
The third contact pins, C1 and C4, are provided to supply a power source voltage VCC and a ground voltage GND to internal circuits of the IC chip 240. The contact pin C1 is used for accepting the power source voltage VCC from the external system for driving the IC chip 240. The contact pin C5 is connected to a pad P5 of the IC chip 240. The contact pin C5 is used for providing an electrical ground GND between the IC chip 240 and the external system. Referring to
The IC chip 240 includes the pads P1˜P8, the ISO7816 interface unit 242, the USB interface unit 244, the MMC interface unit 246, the SWP interface unit 248, an interface selection unit 250, the power management unit 260, and a core block 270.
The power management unit 260 receives the power source voltage VCC and the ground voltage GND respectively from the pads P1 and P5, and supplies the power source voltage VCC and the ground voltage GND into the internal circuits of the IC chip 240.
The core block 270, although not shown in
Referring to
As illustrated in
The following Table 1 summarizes functions of the pads in the smart card 200.
The ISO7816 interface unit 242 receives the reset signal RST through the pad P2 and the clock CLK through the pad P3, and exchanges the input/output data SIO through the pad P7. The ISO7816 interface unit 242 is supplied with the power source voltage VCC through the pad P1, by the power management unit 260, and the ground voltage GND through the pad P5.
The USB interface unit 244 receives the data D+ through the pad P4, via the interface selection unit 250, and outputs the data D− through the pad P8. The USB interface unit 244 is supplied with the power source voltage VCC through the pad P1, via the power management unit 260, and the ground voltage GND through the pad P5.
The MMC interface unit 246 inputs and outputs the data MDATA through the pad P4, via the interface selection unit 250, and receives the clock MCLK through the pad P6, exchanging the command MCMD through the pad P8. The MMC interface unit 246 is supplied with the power source voltage VCC through the pad P1, via the power management unit 260, and the ground voltage GND through the pad P5.
The SWP interface unit 248 receives the signal SWP through the pad P6 via the interface selection unit 250. Since the signal SWP is applied with power thereto, the SWP interface unit 246 need not be supplied with an additional power connection.
The interface selection unit 250 determines an interface mode to the external system by sensing signals input through the first pads P4, P6, and P8 from the external system, and selects one of the interface units 244, 246, and 248 in accordance with a result of the determination. As shown in
If the USB interface mode is selected or determined, the interface selection unit 250 electrically connects the pad P4 for the input data D+ and the pad P8 for the output data D− to the USB interface unit 244.
If the MMC interface mode is selected or determined, the interface selection unit 250 electrically connects the pad P4 for the input/output data MDATA, the pad P6 for the clock CLK, and the pad P8 for the output data D− to the MMC interface unit 246.
If the SWP interface mode is selected or determined, the interface-selection unit 250 electrically connects the pad P6 for the signal SWP to the SWP interface unit 248.
The smart card 200 according to the present invention determines an interface mode to the external system by sensing signals input through the first pads P4, P6, and P8 from the external system, selects one of the interface units in accordance with a result of the determination, and electrically connects a selected interface unit to correspondents of the first pads P4, P6, and P8.
The first multiplexer 252 determines a signal, which is input through the pad P4, into the output data D+ of the USB interface unit 244 or the data MDATA of the MMC interface unit 246 in response to a selection code S1 provided from the mode selection circuit 258.
The second multiplexer 254 determines a signal, which is input through the pad P6, into the output data D− of the USB interface unit 244 or the data MCMD of the MMC interface unit 246 in response to a selection code S2 provided from the mode selection circuit 258.
The third multiplexer 252 determines a signal, which is input through the pad P8, into the signal SWP of the SWP interface unit 248 or the clock MCLK of the MMC interface unit 246 in response to a selection code S3 provided from the mode selection circuit 258.
The mode selection circuit 258 generates the selection codes S1, S2, and S3 for determining an interface mode. Here, the selection codes S1˜S3 may be selected by a user or generated automatically.
A user may set the selection codes S1˜S3 in the following manner. First, the user establishes information about the selection codes S1˜S3 in a register in correspondence each with the interface modes. The selection codes S1˜S3 established in the register are transferred to the mode selection circuit 258.
Therefore, the user can make a selection for rendering the smart card 200 to be operable with a specific interface unit in accordance with the selection codes S1˜S3 established in the register. The following Table 2 exemplarily shows interface units selected by the codes S1˜S3 established in the register.
If the selection codes are set as S1=1, S2=1, and S3=0 in the register, the smart card 200 is used exclusively for communication in the USB interface mode. If the selection codes are set as S1=1, S2=0, and S3=0 in the register, the smart card 200 is used exclusively for communication in the MMC interface mode. If the selection codes are set as S1=1, S2=0, and S3=1 in the register, the smart card 200 is used exclusively for communication in the SWP interface mode.
The mode selection circuit 258 detects signals transferred to the first pads P4, P6, and P8 and generates the selection codes S1˜S3 automatically. For this operation, the mode selection circuit 258 is required to further include an auto-detection circuit for detecting the signals transferred to the first pads P4, P6, and P8.
Signals input by different interface modes are also dissimilar to each other in voltage level. The smart card 200 stores voltage levels of the signals according to the different interface modes. The auto-detection circuit 259 determines an interface mode to the external system by comparing voltage levels of signals of the pads with the values stored in the smart card 200.
Although not shown herein, the auto-detection circuit 259 for detecting impedance gaps of the pads operates as follows. The auto-detection circuit 259 evaluates voltage levels of the pads with varying impedances around the pads to which signals are applied from the external system. Data information of the voltage levels are compared with interface values stored in the smart card 200, from which it determines an interface mode to the external system.
The interface selection unit 250 determines an interface mode from detecting signals of the first pads P4, P6, and P8, selects an interface unit with reference to a result of the determination, and makes electrical connections for pads of the first pads P4, P6, and P8 in correspondence with the selected interface mode.
An interface selection unit 350 includes switches 351˜356 and a mode selection circuit 358. The switches 351˜356 determine and control connections between the first pads P4, P6, and P8 and the interface units 344, 346, and 348 in response to the selection codes S1, S2, and S3 provided from a mode selection circuit 358.
The switch 351 determines to electrically connect the pad P4 with the input data line D+ of the USB interface unit 344 in response to the selection code S1. The switch 352 determines to electrically connect the pad P8 with the output data line D− of the USB interface unit 344 in response to the selection code S2. The switch 353 determines to electrically connect the pad P4 with the data line MDATA of the MMC interface unit 346 in response to the selection code S1. The switch 354 determines to electrically connect the pad P8 with the command line MCMD of the MMC interface unit 346 in response to the selection code S2. The switch 355 determines to electrically connect the pad P6 with the signal line SWP of the SWP interface unit 348 in response to the selection code S3. The switch 356 determines to electrically connect the pad P6 with the clock line MCLK of the MMC interface unit 346 in response to the selection code S3.
The mode selection circuit 358 detects signals transferred to the first pads P4, P6, and P8 and generates the selection codes S1˜S3 to be applied to the switches 351˜356. For this operation, the mode selection circuit 358 is needed to further include an auto-detection circuit.
The auto-detection circuit 359 determines an interface mode to communicate with an external system from sensing signals input to the first pads P4, P6, and P8, and applies the selected code values to the switches 351˜356. The interface selection unit 350 determines to turn the switches 351˜356 on or off in accordance with the selection code values of the auto-detection circuit 359, and electrically connects correspondents of the first pads P4, P6, and P8 to the selected interface unit.
Referring to
If the smart card 300 is to communicate with an external system in the USB interface mode, the auto-detection circuit 359 of the smart card 300 generates the selection codes S1 and S2 from sensing signals input to the pads P4 and P8. The switches 351 and 352 are turned on by the selection codes S1 and S2 generated from the auto-detection circuit 359. Thus, the USB interface unit 344 is automatically connected to the pad P4, which receives the input data D+, and the pad P8 outputting the output data D−. Then, the smart card 300 is able to communicate with the external system in the USB interface mode.
If the smart card 300 is to communicate with an external system in the MMC interface mode, the auto-detection circuit 359 of the smart card 300 generates the selection codes /S1, /S2, and /S3 from sensing signals input to the pads P4, P6, and P8. The switches 353, 354, and 355 are turned on by the selection codes /S1, /S2, and S3 generated from the auto-detection circuit 359. Thus, the MMC interface unit 346 is automatically connected to the pad P4 inputting or outputting the data MDATA, the pad P6 receiving the clock MCLK, and the pad P8 receiving the clock MCLK. Then, the smart card 300 is able to communicate with the external system in the MMC interface mode.
If the smart card 300 is to communicate with an external system in the SWP interface mode, the auto-detection circuit 359 of the smart card 300 generates the selection code S3 from sensing a signal input to the pad P6. The switch 356 is turned on by the selection code S3 generated from the auto-detection circuit 359. Thus, the SWP interface unit 344 is automatically connected to the pad P6 inputting or outputting the signal SWP. Then, the smart card 300 is able to communicate with the external system in the SWP interface mode.
As stated above, the smart card 300 of the present invention generates selection code values to select an interface unit for communication with an external system by sensing signals input to the first pads P4, P6, and P8. Responding to the selection code values, pads of the first pads P4, P6, and P8, corresponding to a selected interface mode, are electrically connected to a selected interface unit, making the smart card 300 communicate with the external system.
Referring to
Next, in a step S20, the smart card 200 operates to electrically connect a selected interface unit with the shared pad so as to enable communication in accordance with the interface mode selected by the step S10. In the step S20, the remaining deselected interface units are electrically disconnected from the shared pad.
Then, in a step S30, the smart card 200 begins to conduct data communication with the external system through the pad connected thereto by the step S20.
Accordingly, the smart card is able to include different interface units, enabling data communication with various external interface units (e.g., 420, 440, 460, and 460) even with a restrictive number of pads.
In summary, the present invention offers a smart card including different kinds of interface units, capable of communicating data with various external interfacing systems even with a restrictive number of contact pins.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
Number | Date | Country | Kind |
---|---|---|---|
10-2006-0063937 | Jul 2006 | KR | national |