Method of transmitting data and a card for such transmission

Abstract

A portable article of the smart card type and a method of transmitting data to such an article. The article comprises an article body and an integrated circuit chip. The integrated circuit chip comprises a central processor unit (CPU) connected via a data and address bus to memories (ROM, RAM, EEPROM), and at least four contact pads (VCC, GND, RST, VPP, CLK, I/O, D+, D−) connected to four contact areas (C 1 , C 5 , C 4 , C 8 ) of a set of at least six contact areas flush with the surface of the card body. Two of the contacts pads (D+, D−) are connected to an interface of the card and are suitable for providing data transmission handled by the central processor unit (CPU) such as for transmitting data using the universal serial bus (USB) protocols and formats.

1 . A portable article of the smart card type, the article comprising firstly a body and secondly an integrated circuit chip ( 9 ), said integrated circuit chip ( 9 ) having a central processor unit (CPU) connected via a data and address bus to memories (ROM, RAM, EEPROM), and further including at least a first contact pad (VCC) suitable for providing the chip ( 9 ) with a power supply voltage, a second contact pad (GND) suitable for grounding the chip ( 9 ), a third contact pad (D+) and a fourth contact pad (D−), said contact pads (VCC, GND, D+, D−) being electrically connected respectively to a first contact area (C 1 ), a second contact area (C 5 ), a third contact area (C 4 ), and a fourth contact area (C 8 ) of a set of eight contact areas (C 1 , C 2 , C 3 , C 4 , C 5 , C 6 , C 7 , C 8 ) flush with the surface of the article body, said portable article comprising the third and fourth contacts pads (D+, D−) connected to an interface of the chip ( 9 ) and suitable for providing data transmission under the control of the central processor unit (CPU).  
   
   
       2 . A portable article according to  claim 1 , wherein the chip ( 9 ) further includes a fifth contact pad (VPP), a sixth contact pad (RST) suitable for resetting the chip ( 9 ), a seventh contact pad (CLK) suitable for providing the chip with a clock signal, and an eighth contact pad (I/O) suitable for inputting and outputting data signals using an asynchronous protocol, said sixth, seventh, and eighth contact pads (RST, CLK, I/O (being connected electrically respectively to a sixth contact area (C 2 ), a seventh contact area (C 3 ), and an eighth contact area (C 7 ) of the set of eight contact areas flush with the surface of the article body.  
   
   
       3 . A portable article according to  claim 1 , wherein the third and fourth pads (D+, D−) constitute a differential pair, the potentials present on said pads being opposite to each other.  
   
   
       4 . A portable article according to  claim 1 , wherein the third and fourth pads (D+, D−) are suitable for transmitting data using protocols defined in the universal serial bus (USB) standard.  
   
   
       5 . A method of transmitting data to an integrated circuit chip ( 9 ) of a portable article of the smart card type including an article body, said integrated circuit chip ( 9 ) comprising a central processor unit (CPU) connected via a data and address bus to memories (ROM, RAM, EEPROM) and further comprising at least a first contact pad (VCC) suitable for providing the chip with a power supply voltage, a second contact pad (GND) suitable for grounding the chip ( 9 ), a third contact pad (D+) and a fourth contact pad (D−), said contact pads (VCC, GND, D+, D−) being electrically connected respectively to a first contact area (C 1 ), a second contact area (C 5 ), a third contact area (C 4 ), and a fourth contact area (C 8 ) of a set of eight contact areas (C 1 , C 2 , C 3 , C 4 , C 5 , C 6 , C 7 , C 8 ) flush with the surface of the article body, wherein the data handled by the central processor unit (CPU) is transmitted via the third and fourth contact pads (D+, D−) connected to an interface of the chip ( 9 ).  
   
   
       6 . A method according to  claim 5 , wherein a fifth contact pad (VPP), a sixth contact pad (RST) resets the chip ( 9 ), a seventh contact pad (CLK) provides the chip ( 9 ) with a clock signal, and an eighth contact pad (I/O) provides data signal input and output using an asynchronous protocol, said sixth, seventh, and eighth contact pads (RST, CLK, I/O) being electrically connected respectively to a sixth contact area (C 2 ), a seventh contact area (C 3 ), and an eighth contact area (C 7 ) of the set of eight contact areas flush with the surface of the card body.  
   
   
       7 . A method according to  claim 5 , wherein the third and fourth contact pads (D+, D−) constitute a differential pair.  
   
   
       8 . A method according to  claim 5 , wherein the data transmission via the third and fourth pads (D+, D−) takes place in both directions in alternation.  
   
   
       9 . A method according to  claim 5 , wherein to process data transmitted via the third and fourth contact pads (D+, D−), a clock is generated internally in the chip.  
   
   
       10 . A method according to  claim 5 , wherein data is transmitted via the third and fourth contact pads (D+, D−) using asynchronous communications protocol.  
   
   
       11 . A method according to  claim 5 , wherein data transmission is provided at rates going up to a value of about 12 megabits per second.  
   
   
       12 . A method according to  claim 5 , wherein data transmission is provided using protocols in compliance with the universal serial bus (USB) standard.  
   
   
       13 . A method according to  claim 5 , wherein in order to transmit data via the third and fourth pads (D+, D−), the portable article is connected to a connector of a reader ( 2 ) in such a manner that initially connection is made to the second contact area (C 5 ), then connection to the third and fourth contact areas (C 4 , C 8 ), and finally connection to the first contact area (C 1 ).