JPH09223203A - Non-contact ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact IC card capable of eliminating the queuing time of a reader/writer and efficiently executing access to a memory and data transfer to/from the reader/writer. SOLUTION: A command processing part 12 in the non-contact IC card 1 executes internal processing including address specification for accessing a non-volatile memory 15, the check of command validity and the check of address validity in parallel with the reception of a command byte from the reader/writer 3. The command processing part 12 executes also data writing in the memory 15 and data reading out of the memory 15 in parallel with data transfer to/from the reader/writer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact IC card for exchanging information with a reader / writer by wireless communication.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing the configuration of a general non-contact IC card system. In this figure, 1
Is a non-contact IC card, and 2 is a personal computer (hereinafter referred to as PC). Reference numeral 3 is a reader / writer, which is used to write data to the non-contact IC card 1 or read data from the non-contact IC card 1 under the control of the PC 2.
Sends and receives commands and data to and from.

FIG. 4 is a block diagram showing the internal structure of the non-contact IC card 1. As shown in the figure, non-contact IC
The card 1 includes a transmission / reception unit 11, a command processing unit 12, a register unit 13, a memory control unit 14, and a nonvolatile memory 1.
5. The transmission / reception unit 11 is means for wirelessly exchanging signals with the reader / writer 3. The command processing unit 12 receives commands and data from the reader / writer 3 or transmits data and various information to the reader / writer 3 via the transmitting / receiving unit 11. The command processing unit 12 is a control center of the non-contact IC card 1, interprets a command received from the reader / writer 1, and writes / reads data in the non-volatile memory 15 based on the result. In addition, the communication with the reader / writer 3 is controlled. The register unit 13 is used by the command processing unit 12 as a storage unit for control information and the like.

The nonvolatile memory 15 has a clock signal SC.
An input terminal for receiving K and this clock signal SC
It has a bidirectional data terminal for transmitting and receiving a 1-bit data signal SD in synchronization with K. Non-volatile memory 15
The write data and the like are supplied to the nonvolatile memory 15 serially bit by bit as the data signal SD. Further, read data or the like for the non-volatile memory 15 is serially output bit by bit as the data signal SD. Further, the non-volatile memory 15 has a large number of memory addresses, but it is necessary to give a slave address and a word address to the non-volatile memory 15 in order to specify a memory address for writing or reading data. is there. Each of these addresses is also serially supplied to the nonvolatile memory 15 as a data signal SDA bit by bit. The slave address is
In addition to the bit for specifying the memory address, a mode designation bit for designating whether the type of access is write or read is also included, and the operation mode of the nonvolatile memory 15 depends on the content of this mode designation bit. Is set to the write mode or the read mode. Such access to the nonvolatile memory 15 is performed via the memory control unit 14 under the control of the command processing unit 12.

Next, the operation of this non-contact IC card system will be described. FIG. 5 illustrates a format of transfer information between the reader / writer 3 and the non-contact IC card 1 at the time of executing a write command for writing data to the non-contact IC card 1 and at a time of executing a read command for reading data from the non-contact IC card 1. It was done. In this system, data transfer between the reader / writer 3 and the non-contact IC card 1 is performed in 1-byte units. Therefore, the command is divided into 1 command byte each, and
The data is also divided into 1-byte data bytes and transmitted / received in 1-byte units. Status is reader / writer 3
The non-contact IC card 1 which has received the command from this is information to be transmitted to report the current status, and this status is also transferred to the reader / writer 3 in 1-byte units.

Each command byte, data byte, etc. is 11 bits consisting of a start bit of 1 bit, transfer data of 8 bits (command, data or status), a parity bit of 1 bit, and a stop bit of 1 bit. It is composed of information. These one
As shown in FIG. 6A, the information consisting of 1 bit is synchronized with the clock from the reader / writer 3 to the non-contact IC card 1
Are serially transferred to. Data transfer from the non-contact IC card 1 to the reader / writer 3 is also serially performed bit by bit as shown in FIG. 6B. As shown in these figures, 11 clocks are required to transfer a 1-byte command or data between the reader / writer 3 and the non-contact IC card 1.

In the non-contact IC card 1, the command bytes and data bytes serially transferred from the reader / writer 3 as described above are delivered to the command processing unit 12 via the transmission / reception unit 11. Then, the command processing unit 12
If the command delivered to the non-volatile memory 15 is a write command, data is written to the non-volatile memory 15, and if the command is a read command, the non-volatile memory 15
The data is read from. The access to the non-volatile memory 15 is performed according to the control sequence shown in FIG.

First, before writing or reading data, the memory control unit 14 causes the clock signal SCK to go high for two clock cycles, as shown in FIG. 7A.
The data signal SD falls to the level and the data signal SD falls during the period in which the clock SCK maintains the H level. In this way, the start condition information declaring the start of access is given to the non-volatile memory 15. After the supply of the start condition information, the access to the non-volatile memory 15 is started.

When writing or reading data, it is necessary to give a write address or a read address of data to the non-volatile memory 15. These addresses are given to the non-volatile memory 15 before writing or reading data. Then, after the addressing is completed, the write data is supplied to the non-volatile memory 15 or the data is read from the non-volatile memory 15.

Access (read / write) to the nonvolatile memory 15 is also performed in 1-byte units.
Here, as shown in FIG. 7B, it is necessary to send and receive 8-bit data and 1-bit Ack bit for a total of 9 bits in 1-byte access. Therefore, it takes 9 clocks to transfer 1 byte of data to and from the nonvolatile memory 15.

When the writing or reading of data in the non-volatile memory 15 is completed, the memory control unit 14 sets the clock signal SCK to the H level for two clock cycles as shown in FIG. The data signal SD rises during the period in which the clock SCK maintains the H level. In this way, the stop condition information declaring the end of access is given to the non-volatile memory 15, and thereby the access to the non-volatile memory 15 is ended.

FIG. 8 shows an operation sequence of the entire non-contact IC card system. FIG. 8A shows an operation at the time of executing a write command, and FIG. 8B shows an operation at the time of executing a read command. .

When executing the write command, first, the command bytes 1 to 6 are transferred from the reader / writer 3 to the non-contact IC card 1.
Are sequentially transferred. Then, the non-contact IC card 1 executes an internal process, that is, interprets this series of commands and executes various processes necessary for data reception such as start condition information and address supply to the nonvolatile memory 15. While this internal processing is performed, the reader / writer 3 waits for a response from the non-contact IC card 1. And
Data bytes 1 to N are sequentially transferred from the reader / writer 3 to the non-contact IC card 1 as the internal processing is completed,
The data is sequentially written in the non-volatile memory 15. And
The non-contact IC card 1 performs an internal process for ending the writing of data, and then the status is transmitted to the reader / writer 3. This completes the execution of the write command. When executing a read command, after the command data is transferred, the non-contact IC card 1 performs an internal process to prepare for reading the data, and after this internal process, a status is transmitted, and after this transmission. ,
The transfer of data bytes from the non-contact IC card 1 to the reader / writer 3 is started by further performing internal processing.

[0014]

As described above, in the conventional non-contact IC card system, data transfer with the reader / writer is awaited due to internal processing of the non-contact IC card. It was an obstacle to speeding up.

The present invention has been made in view of the circumstances described above, and eliminates the waiting time of the reader / writer,
It is an object of the present invention to provide a non-contact IC card that can efficiently access a memory and transfer data with a reader / writer.

[0016]

DISCLOSURE OF THE INVENTION In parallel with receiving a command from a reader / writer, the present invention includes an internal method for specifying an address for accessing a memory, a command validity check, and an address validity check. A gist of a non-contact IC card that performs data writing to the memory and data reading from the memory in parallel with performing data transfer with the reader / writer.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A non-contact IC card according to an embodiment of the present invention will be described below with reference to the drawings.
The contactless IC card according to the present embodiment is basically composed of a transmission / reception unit 11, a command processing unit 12, a register unit 13, a memory control unit 14, and a non-volatile memory 15, similar to the one shown in FIG. However, it is significantly different from that in the prior art in that the following control method is adopted. a. In parallel with receiving the command from the reader / writer 3, an internal process including designation of an address for accessing the nonvolatile memory 15, command validity check, and address validity check is performed. B. In parallel with data transfer with the reader / writer 3, data is written to the nonvolatile memory 15 or data is read from the memory.

1 and 2 are operation sequence diagrams of the non-contact IC card according to this embodiment. Hereinafter, the operation of the present embodiment will be described with reference to these drawings.

(1) Operation during execution of write command First, the operation of the present embodiment during execution of a write command will be described with reference to the operation sequence diagram of FIG. In the present embodiment, the reader / writer 1 sequentially and continuously transmits command bytes 1 to 6 and data batches 1 to N without waiting time. These pieces of information are sent to the command processing unit 12 via the transmission / reception unit 11 of the non-contact IC card 1 and handled as follows.

First, the command byte 1 transmitted from the reader / writer 3 is the command type, that is, the command code for specifying the write command in this case, and the upper address of the memory address of the nonvolatile memory 15 to be accessed. Address and. Non-contact IC card 1
By receiving the command byte 1, the command processing unit 12 recognizes that data writing to the nonvolatile memory 15 is requested.

The command code 2 to be transmitted next includes the lower address of the memory address. The command processing unit 12 transmits the start condition information to the non-volatile memory 15 via the memory control unit 14 in parallel with receiving the command byte 2. The transmission of the start condition information has already been described with reference to FIG.

The command code 3 to be transmitted next includes the number N of bytes of the transfer data transmitted from the reader / writer 3. The command processing unit 12 transmits the slave address to the non-volatile memory 15 via the memory control unit 14 in parallel with receiving the command byte 3. That is, although the memory address to be accessed is already determined by the upper address and the lower address acquired from the reader / writer 3, the address designation of the non-volatile memory 15 in the non-contact IC card 1 is performed by the slave address as already described. And the word address are sequentially specified. Therefore, a slave address and a word address are created based on the memory address determined by the upper address and the lower address, and the former slave address is first clock signal S.
In synchronization with CK, the data signal SD is serially sent bit by bit to the nonvolatile memory 15 (FIG. 7).
(B)). Here, the slave address includes the mode designation bit as described above, and a value corresponding to the write mode is set in this bit.

Thereafter, command bytes 4 to 6 to be transmitted
Is composed of other additional information. First, the command processing unit 12 sends the word address to the non-volatile memory 15 in parallel with receiving the command byte 4. Next, the command processing unit 12 checks the validity of the memory address specified by the command bytes 1 and 2 already received in parallel with receiving the command byte 5. Next, the command processing unit 12 receives the command byte 6 and performs a validity check on whether the command received this time from the reader / writer 3 is valid or not.

As described above, in this embodiment, when the reception of the command byte from the reader / writer 3 is completed, the validity check of the command and the validity check of the address are completed, and the address designation to the nonvolatile memory 15 is performed. Completed. Therefore, immediately after receiving the command byte 6, the data bytes 1 to N can be immediately transmitted without waiting.
(That is, the write data for the non-volatile memory 15) can be received from the reader / writer 3. In addition, in the present embodiment, while the data bytes are being received from the reader / writer 3, the data bytes that have already been received are sent to the non-volatile memory 15, so that the data bytes can be received without waiting time. . Specifically, it is as follows.

First, the command processing section 12 receives the first data byte 1 from the reader / writer 3 after the command byte 6. At this point, the command processing unit 12 stores a value obtained by subtracting 1 from the already received data byte number N in the register unit 13 (see FIG. 3). Next, in parallel with receiving the data byte 2, the command processing unit 12 synchronizes the data byte 1 received immediately before with the clock signal SCK and serially sends the data byte 1 bit by bit to the nonvolatile memory 15 ( See FIG. 7B). Also,
With the transmission of the data byte 1, the number of data bytes stored in the register unit 13 is decremented by 1.

The same applies to the subsequent data bytes k (k = 3 to N), and the command processing unit 12 receives the data byte k and, in parallel with the reception of this data byte, the data byte k-1 is non-volatile. The process of sending to the memory 15 and decrementing the number of data bytes in the register unit 13 is repeated. When the reception of all the data bytes 1 to N is completed, the number of data bytes in the register unit 13 becomes zero. When the command processing unit 12 sends the last data byte N to the nonvolatile memory 15, the command processing unit 12 sends the status to the reader / writer 3, and at the same time, sends the stop condition information to the nonvolatile memory 15. With the above, the execution of the write command for writing the data bytes 1 to N to the nonvolatile memory 15 is completed.

(2) Operation during execution of read command Next, the operation of the present embodiment during execution of the read command will be described with reference to the operation sequence diagram of FIG.
First, the reader / writer 1 sequentially and continuously transmits command bytes 1 to 6. These pieces of information are sent to the command processing unit 12 via the transmission / reception unit 11 of the non-contact IC card 1 and handled as follows.

The command byte 1 transmitted first includes the type of command, that is, the command code specifying the read command in this case, and the upper address of the memory address of the nonvolatile memory 15 to be accessed. . By receiving this command byte 1, the command processing unit 12 of the non-contact IC card 1 recognizes that data reading from the non-volatile memory 15 is requested.

The command byte 2 to be transmitted next contains the lower address of the memory address. The command processing unit 12 transmits the start condition information to the non-volatile memory 15 via the memory control unit 14 in parallel with receiving the command byte 2.

The command byte 3 to be transmitted next contains the number N of data bytes that the reader / writer 3 is going to read. The command processing unit 12 uses this command byte 3
The slave address corresponding to the above memory address is transmitted to the non-volatile memory 15 in parallel with the reception of the slave address. A value corresponding to the write mode is set in the mode designation bit in this slave address.

Thereafter, the command bytes 4 to 6 to be transmitted
Is composed of other additional information. First, the command processing unit 12 sends the word address corresponding to the memory address to the non-volatile memory 15 in parallel with receiving the command byte 1. Then the command processing unit 1
In parallel with receiving the command byte 5, 2 checks the validity of the memory address specified by the already received command bytes 1 and 2 and sends the start condition information to the non-volatile memory 15. Next, the command processing unit 12 receives the command byte 6 in parallel,
The validity of the command received this time from the reader / writer 3 is checked and the slave address is sent to the non-volatile memory 15. A value corresponding to the read mode is set in the mode designation bit in this slave address. As a result of the slave address being transmitted twice as described above, the non-volatile memory 15 is set to an operation mode in which data stored in consecutive memory addresses starting from the already addressed memory address is continuously read. .

As described above, in this embodiment, the validity check of the command and the validity check of the address are completed when the reception of the command byte 6 is completed, and the designation of the address to be accessed to the non-volatile memory 15 is also completed. . Therefore, the data can be read from the non-volatile memory 15 immediately after receiving the stop bit of the command byte 6.

That is, in the present embodiment, the command processing section 12 sends the status to the reader / writer 3 immediately after receiving the command byte 6, and at the same time, reads the first data from the non-volatile memory 15.
Next, in parallel with transmitting the data read from the non-volatile memory 15 to the reader / writer 3, the next data is read from the non-volatile memory 15. After that, reader / writer 3
The same processing is repeated until the reading and transmission of the data corresponding to the number N of data bytes received from are completed. Then, while the last data byte N is being sent to the reader / writer 3, the stop condition information is sent to the non-volatile memory 15, and a series of memory access sequence is completed. As described above, in the present embodiment, read data is supplied to the reader / writer 3 without waiting time.

In the above-described operation, if the command from the reader / writer 3 is found to be incorrect or if an error such as a parity error occurs, the memory access sequence is normally terminated.
The memory access sequence will be continued during the error processing.

[0035]

As described above, according to the contactless IC card of the present invention, in parallel with receiving the command from the reader / writer, the address for accessing the memory is specified and the validity of the command is checked. In addition to performing internal processing including address validity check and data transfer with the reader / writer, the reader / writer is waited for data writing to the memory or data reading from the memory. There is an effect that the memory can be efficiently accessed and the data can be transferred to and from the reader / writer without performing the above operation.

[Brief description of drawings]

FIG. 1 is an operation sequence diagram showing an operation of a non-contact IC card according to an embodiment of the present invention.

FIG. 2 is an operation sequence diagram showing an operation of the non-contact IC card.

FIG. 3 is a block diagram showing a configuration of a general non-contact IC card system.

FIG. 4 is a block diagram showing a configuration of a general non-contact IC card.

FIG. 5 is a diagram showing a data format of information exchanged between a non-contact IC card and a reader / writer.

FIG. 6 is a waveform diagram showing data transfer performed between a non-contact IC card and a reader / writer.

FIG. 7 is a waveform diagram showing an access procedure of a nonvolatile memory in the non-contact IC card.

FIG. 8 is an operation sequence diagram showing an operation of a conventional non-contact IC card.

[Explanation of symbols]

 1 Non-contact IC Card 3 Reader / Writer 11 Transmitter / Receiver 12 Command Processor 14 Memory Controller 15 Nonvolatile Memory

Claims (1)

[Claims] 1. In parallel with receiving a command from a reader / writer, internal processing including address specification for accessing a memory, command validity check and address validity check is performed, and the reader / writer is also provided. A non-contact IC card, wherein data is written to or read from the memory in parallel with data transfer between the memory and the data.