Card system, IC card and card reader/writer used for the card system

• US 6,655,588 B2
• Filed: 07/27/2001
• Issued: 12/02/2003
• Est. Priority Date: 07/28/2000
• Status: Expired due to Fees

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Fukazawa, Hiroshi
• Primary Examiner(s): Frech, Karl D.
• Assistant Examiner(s): Caputo, Lisa M.
• Application Number:
  US09/916,944
• Publication Number:
  US 20020020744A1
• Time in Patent Office: 858 Days
• Field of Search: 235/437, 235/492, 395/825, 371/29.1
• US Class Current: 235/437
• CPC Class Codes: G06K 7/0013 by galvanic contacts, e.g. card connectors for ISO-7816 compliant smart cards or memory cards, e.g. SD card readers connectors in general H01R13/00; connectors for SIM cards used in mobile phones or the like H04B1/3816
• CPC Class Codes: G06K 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00
• CPC Class Codes: H04L 1/0063 Single parity check
• CPC Class Codes: H04L 1/1692 Physical properties of the supervisory signal, e.g. acknowledgement by energy bursts
• CPC Class Codes: H04L 1/1803 Stop-and-wait protocols
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end

Abstract

A card system having an IC card and a card reader/writer wherein when data is transmitted and received over a signal line between the IC card and the card reader/writer for reading or writing of the data, a data transmitting side transmits a parity based upon content of the data together with the data over the signal line and a data receiving side checks whether or not there is any error in reception of data based upon content of the a data and the parity received to transmit back to the data transmitting side a data retransmission request signal for requesting the data transmitting side to retransmit the data when there is an error; and wherein the IC card corrects a level of the signal line for requesting the data transmitting side to transmit next data when it is verified that there is no error in the reception of the data based upon content of the data and the parity received by the data receiving side.

Claims

1. A card system comprising an integrated circuit (IC) card having a port terminal to be electrically connected to a port terminal of a card reader/writer for transmitting and receiving data over a signal line between said IC card and said card reader/writer to read data from or write data to said IC card, said card system comprising:

a data transmitting side, which is one of said IC card and said card reader/writer, transmitting a parity based upon content of the data together with the data over the signal line;

a data receiving side, which is another of said IC card and said card reader/writer, checking whether or not there is any error in reception of data based upon content of the data and the parity received, said data receiving side further transmitting back to the data transmitting side a data retransmission request signal for requesting the data transmitting side to retransmit the data to said data receiving side when an error in the reception of data is detected; and

said IC card correcting a voltage level of said signal line to enable the data receiving side to request the data transmitting side to transmit next data to the data receiving side when it is verified that there is no error in the reception of said data based upon content of said data and said parity received by the data receiving side, wherein transmission and reception of data over the signal line is enabled at a transmission rate for which voltage delay time on the signal line that corresponds to a predetermined voltage level for transmission and reception of data over the signal line exceeds data delay time that corresponds to input of data to be transmitted at the predetermined voltage level over the signal line.

2. The card system as defined in claim 1, wherein in case of said IC card being the data receiving side, the voltage level of the signal line is corrected during an interval from a reception of said parity by the data receiving side to a reception of said data retransmission request signal by the data transmitting side.

3. The card system as defined in claim 1, wherein the transmission rate is 1,228,800 bits/second.

4. A card system comprising an integrated circuit (IC) card having a port terminal to be electrically connected to a port terminal of a card reader/writer for transmitting and receiving data over a signal line between said IC card and said card reader/writer to read data from or write data to said IC card, said card system comprising:

a data transmitting side, which is one of said IC card and said card reader/writer, transmitting a parity based upon content of the data together with the data over the signal line;

a data receiving side, which is another of said IC card and said card reader/writer, checking whether or not there is any error in reception of data based upon content of the data and the parity received, said data transmitting side further transmitting back to the data transmitting side a data retransmission request signal for requesting the data transmitting side to retransmit the data to said data receiving side when an error in the reception of data is detected; and

said IC card correcting a voltage level of said signal line to enable the data receiving side to request the data transmitting side to retransmit said data to the data receiving side, after the data receiving side transmits said data retransmission request signal to the data transmitting side, wherein transmission and reception of data over the signal line is enabled at a transmission rate for which voltage delay time on the signal line that corresponds to a predetermined voltage level for transmission and reception of data over the signal line exceeds data delay time that corresponds to input of data to be transmitted at the predetermined voltage over the signal line.

5. The card system as defined in claim 4, wherein in case of said IC card being the data transmitting side, the voltage level of said signal line is corrected at a predetermined timing before next data is transmitted from the data transmitting side to the data receiving side.

6. The card system as defined in claim 4, wherein the transmission rate is 1,228,800 bits/second.

7. An integrated circuit (IC) card for use in a card system comprising a card reader/writer having a port terminal to be electrically connected to a port terminal port of said IC card for transmitting and receiving data over a signal line between said IC card and a card reader/writer to read data from or write data to said IC card, said card system comprising a data transmitting side, which is one of said IC card and said card reader/writer, for transmitting a parity based upon content of the data together with the data over the signal line, and a data receiving side, which is another of said IC card and said card reader/writer, for checking whether or not there is any error in reception of data based upon content of the data and the parity received, said data receiving side for further transmitting back to the data transmitting side a data retransmission request signal to request the data transmitting side to retransmit the data to said data receiving side when an error in the reception of data is detected, said IC card comprising:

a means for correcting a voltage level of said signal line to enable the data receiving side to request the data transmitting side to transmit next data when it is verified that there is no error in the reception of said data based upon content of said data and said parity received by the data receiving side, wherein transmission and reception of data over the signal line is enabled at a transmission rate for which voltage delay time on the signal line that corresponds to a predetermined voltage level for transmission and reception of data over the signal line exceeds data delay time that corresponds to input of data to be transmitted at the predetermined level over the signal line.

8. The integrated circuit (IC) card for use in a card system comprising a card reader/writer as defined in claim 7, said card reader/writer comprising means for transmitting and receiving data for writing and reading the data to and from said IC card.

9. The integrated circuit (IC) for use in a card system as defined in claim 7, wherein the transmission rate is 1,228,800 bits/second.

10. An integrated circuit (IC) for use in a card system comprising a card reader/writer having a port terminal to be electrically connected to a port terminal of said IC card for transmitting and receiving data over a signal line between said IC card and a card reader/writer to read data from or write data to said IC card, said card system comprising a data transmitting side, which is one of said IC card and said card reader/writer, for transmitting a parity based upon content of the data together with the data over the signal line, and a data receiving side, which is another of said IC card and said card reader/writer, for checking whether or not there is any error in reception of data based upon content of the data and the parity received, said data receiving side further for transmitting back to the data transmitting side a data retransmission request signal to request the data transmitting side to retransmit the data to said data receiving side when an error in the reception of data is detected, said IC card comprising:

a means for correcting a voltage level of said signal line to enable the data receiving side to request the data transmitting side to retransmit said data to the data receiving side, after the data receiving side transmits said data retransmission request signal to the data transmitting side, wherein transmission and reception of data over the signal line is enabled at a transmission rate for which voltage delay time on the signal line that corresponds to a predetermined voltage level for transmission and reception of data over the signal line exceeds data delay time that corresponds to input of data to be transmitted at the predetermined voltage level over the signal line.

11. The integrated circuit (IC) card for use in a card system comprising a card reader/writer as defined in claim 10, said card reader/writer comprising means for transmitting and receiving data for writing and reading the data to and from said IC card.

12. The integrated circuit (IC) for use in a card system as defined in claim 10, wherein the transmission rate is 1,228,800 bits/second.

13. A card system comprising an integrated circuit (IC) card and a card reader/writer, said IC card comprising at least a CPU, a memory for storing a program and/or data, a port terminal for data input and output, a terminal for receiving a clock signal, and a plurality of power supply terminals, said terminals being connected to said CPU of said IC card, said card reader/writer comprising at least a CPU, a port terminal for data input and output, a terminal for providing a clock signal, and a plurality of power supply terminals for supplying a power and a ground, said terminals being connected to said CPU of said card reader/writer, each of said terminals of said IC card to be elecirically connected to a corresponding terminal of said card reader/writer when said IC card is mounted on said card reader/writer, said card system comprising:

a data transmitting side, which is one of said IC card and said card reader/writer, transmitting a data comprised of a series of data bits accompanied by an error chek code over a signal line arranged between said CPU of said IC card and said CPU of said card reader/writer through said port terminal of said IC card and said port terminal of said card reader/writer, said error check code calculated based on content of the data bits;

a data receiving side, which is another of said IC card and said card reader/writer, checking for any error in reception of data by calculating an error check code based upon content of the data bits received and comparing the calculated error check code with said received error check code, said data receiving side further transmitting back to the data transmitting side a data retransmission request signal for requesting the data transmitting side to retransmit the data to said data receiving side when an error in the reception of data is detected; and

said IC card comprising means for correcting a voltage level of said signal line to a predetermined voltage level, when it is verified by the data receiving side that there is no error in the reception of said data based upon said error check code, said correction of the voltage level of said signal line causing the data transmitting side to correctly detect that a data retransmission request signal from the data receiving side is not transmitted at a timing of inputting next data to said signal line by the data transmitting side, wherein transmission and reception of data over the signal line is enabled at a transmission rate for which voltage delay time on the signal line that corresponds to the predetermined voltage level for transmission and reception of data over the signal line exceeds data delay time that corresponds to input of data to be transmitted at the predetermined voltage level over the signal line.

14. The card system as defined in claim 13, wherein said IC card further comprises means for correcting a voltage level of said signal line after the data receiving side transmits said data retransmission request signal to request the data transmitting side to retransmit said data to the data receiving side.

15. The card system as defined in claim 13, wherein said IC card further comprises means for correcting the voltage level of the signal line during an interval from a reception of said error check code by the data receiving side to a reception of said data retransmission request signal by the data transmitting side, in case of said IC card being the data receiving side.

16. The card system as defined in claim 13, wherein said IC card further comprises means for correcting the voltage level of said signal line at a predetermined timing before next data is transmitted from the data transmitting side to the data receiving, in case of said IC card being the data transmitting side.

17. The card system as defined in claim 13, wherein said error check code comprises a parity bit.

18. The card system as defined in claim 13, wherein a start bit is transmitted on the signal line ahead of said data bits from the data transmitting side to the data receiving side.

19. The card system as defined in claim 13, wherein the transmission rate is 1,228,800 bits/second.