JPH04347788A - Ic memory card - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC memory card incorporating an IC (integrated circuit) memory.

More specifically, the present invention provides an IC memory for storing data, a method for preventing data from being read out illegally, and a method for detecting whether the IC memory card is a genuine product or a copy from the main body. The present invention relates to an IC memory card having a built-in dedicated control circuit for identifying the IC memory card.

[0003] Here, the term "genuine product" refers to one manufactured by legitimate means, and the term "copy product" refers to one manufactured by a third party who does not have the right to legitimately manufacture the IC memory card.

0004

[Prior Art] Conventionally, as an IC memory card with built-in IC memory, for example, mask ROM, EP (OTP)
) Types with built-in ROM, EEPROM, and SRAM are known.

FIG. 13 shows a 256 kilobit OTP
A conventional example of an IC memory card using ROM will be described. In such conventional examples, for example, by manufacturing a terminal conversion adapter that converts the terminal arrangement of a card to that of a DIP IC, it is possible to easily read and write data using a PROM programmer, etc. Put it away.

[0006]Therefore, there was a risk that the data in the card could be read out by a third party who did not have the right to legally manufacture the IC memory card, and that copies could easily be manufactured.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent data from being read out illegally and to identify from the main body whether the IC memory card is a genuine product or a copy. An object of the present invention is to provide an IC memory card having a built-in dedicated control circuit for the purpose of the present invention.

[0008]

[Means for Solving the Problems] An IC memory card according to the present invention is an IC memory card equipped with an IC memory that becomes operational when a control signal of a specific level is applied to a chip enable terminal. control signal determining means for outputting a determination signal of a predetermined level only when the plurality of supplied control signals instruct password input determination; holding means for holding an address signal and a data signal, respectively; password determining means for outputting a matching signal when the signals held in the holding means match a predetermined password; and password determining means for outputting a matching signal. and then, when a signal instructing access to the IC memory is given from the main device side, a memory control means sets a chip enable terminal of the IC memory to a specific level to put the IC memory into an operating state. It is equipped with

[0009] Another IC memory card according to the present invention is an IC memory card equipped with an IC memory that becomes operational when a control signal of a specific level is applied to a chip enable terminal. control signal determining means for outputting a determination signal of a predetermined level only when the plurality of control signals instructing password input determination; Holding means for holding an address signal and a data signal, respectively; and a password determination for outputting a matching signal for identifying the password when the signal held in the holding means matches one of a plurality of passwords. Means and specific card ID
The device is equipped with an ID register for storing information, and a control means that enables access to the IC memory or reading from the ID register depending on the type of the coincidence signal.

0010

[Operation] According to the present invention, the dedicated control circuit works to prevent the IC memory from becoming operational unless a specific signal equivalent to a password is input from the main unit. It is possible to prevent the data from being read and copy products being manufactured.

[0011] Furthermore, in the present invention, only when a specific password is input, the card ID unique to the IC memory card is
can be read out.

That is, in the present invention, the I
In addition to the IC memory, it is equipped with a dedicated control circuit to prevent unauthorized copy products from being manufactured, and unless a password is entered from the main unit, this dedicated control circuit will automatically store the card ID unique to the IC memory card. or read out the
Also, prevent the IC memory from entering the operating state, and
The feature is that reading and writing operations to memory are not possible. Here, the password refers to a specific signal for reading out the card ID or putting the IC memory into operation to enable reading and writing.

[0013]

Embodiment Embodiment 1 FIG. 1 is a block diagram showing a first embodiment of the present invention. 2 and 3 are circuit diagrams showing FIG. 1 in more detail.

In the first embodiment shown in FIGS. 1, 2, and 3, a control signal determination circuit 1, an address signal holding circuit 2, and a data signal holding circuit 3 are provided between the IC memory card terminal and the IC memory card terminal. , an address X determination circuit 4, a data DX determination circuit 5, and an inverted CE output control circuit 6.

The IC memory 7 in this embodiment has 25
A 6 kilobit OTP ROM is used, and the memory configuration is as shown in the memory map of FIG.

Further, the operation mode when this IC memory 7 is used is as shown in FIG. However, in this embodiment, by the normal access method (that is, by setting only the levels of various control signals),
It is impossible to access the IC memory 7. The detailed reason is as described below.

In FIGS. 1 to 3, A15 is an address signal for switching between the IC memory side and the dedicated control circuit side, and uses the highest address signal of the IC memory. When this A15 is "L", the IC memory 7 can be accessed (see FIG. 5. However, direct access is not possible and a password must be entered in advance), and "H" When this happens, you can enter the password.

Reference numeral 1 denotes a control signal determination circuit, which outputs an "L" level when a write command is issued from the main body when A15 is at an "H" level. 2 and 3
is a holding circuit for address and data signals, and the signal from the control signal determination circuit 1 changes from "L" level to "
This circuit holds the address and data signals input at that time when the signal rises to the H'' level.

4 and 5 are address and data signal determination circuits, in which the signals held in the address signal holding circuit 2 and the data signal holding circuit 3 are X, DX, respectively.
In other words, only when the password matches, “H”
”Output the level.

6 is an inverted CE (chip enable) output circuit, and when the outputs from the determination circuits 4 and 5 are at the "H" level, the main body outputs the "L" level to A15 and the "L" level to the inverted CE.
When the "L" level is input, the "L" level is input to the inverted CE terminal of the IC memory 7, and the IC memory 7 enters the operating state, making it possible to read and write the IC memory.

[0021] Therefore, inputting a specific signal serving as a password from the main body to the address bus and data bus,
That is, only by inputting a command to write the specific data DX to the specific address X, can the IC memory 7 be brought into operation, and can the IC memory 7 be read and written.

[0022] In this way, the data cannot be read out with a general-purpose reading device, so that it is possible to prevent unauthorized copy products from being manufactured.

As described above, in this embodiment, the output signal is set to "L" only when the IC memory and the control signal are specified.
”, and an address signal holding circuit that holds the address signal and data signal from the main unit as output signals when the output signal from the control signal judgment circuit switches from “L” to “H”. circuit, a data signal holding circuit, and an address signal judgment circuit and a data signal judgment circuit that output "H" level only when the output signals from the address signal holding circuit and the data signal holding circuit are specific, All outputs from the signal judgment circuit and data signal judgment circuit are “
Only when the control signal from the main unit (inverted CE) and address control signal A15 are “L”, the IC
The inverted CE output control circuit that outputs an "L" signal to the inverted CE input terminal of the memory enables read/write operations to the IC memory.

In other words, even if the control signal (inverted CE) is input to "L" from the main body in order to operate the IC memory from the main body, this dedicated control circuit will not work unless the password is input from the main body. , "H" is input to the inverted CE terminal of the IC memory, and the IC memory is not in an operating state and cannot be read or written. Therefore, the data cannot be read unless the reading device has a password input function, so it is possible to prevent the data from being read out illegally by a general-purpose reading device or the like.

[0025] In the first embodiment described above,
The inverted CE signal is controlled by a dedicated control circuit, but by controlling the inverted OE (output enable) signal, IC memory can only be written to before entering a password, and can also be read by entering a password. It is also possible to implement a card. Invert this to P
If implemented using the GM signal, it is also possible to realize an IC memory card that can only be read before a password is input, and can also be written when a password is input, contrary to the above-described operation.

Embodiment 2 In the first embodiment described above, a password must be entered before accessing the IC memory. In the second embodiment described here, in addition to the above-mentioned memory access, the card ID unique to the IC memory card is read out by inputting a password.

The second embodiment includes an IC memory, a control signal determination circuit that outputs an "L" signal only when the control signal is specified, and an output signal from the control signal determination circuit that changes from "L" to "L". When switching to "H", the address signal holding circuit and data signal holding circuit that hold the address signal and data signal from the main unit as output signals, and the output signals from the address signal holding circuit and data signal holding circuit are specified. Only if “
The device is characterized in that it has an address signal determination circuit and a data signal determination circuit that output an H" level, and can control card ID reading and reading and writing of IC memory data by the address signal determination circuit and data signal determination circuit. It is.

More specifically, in the second embodiment, in addition to the IC memory for storing data, there is also an IC memory for preventing data from being read out illegally.
Equipped with a dedicated control circuit to identify whether the memory card is a genuine product or a copy, by entering passwords X, Y, and Z from the main unit, NOR
It is possible to switch to MAL mode (IC memory read/write mode), switch to ID mode (card ID readable mode), and read the card ID, and a password that does not match any of X, Y, or Z. The feature is that by inputting , it is possible to switch to the RESET mode (a mode in which none of the above three types is possible).

That is, as shown in FIG. 11, by inputting the password Y from the main body and switching to the ID mode, the card ID can be output by the ID output control circuit in this dedicated control circuit. In this state, by inputting the password Z, the card ID is output from the ID register in the dedicated control circuit. By identifying this card ID on the main body, it is possible to know whether it is a genuine product or a copy product.

Furthermore, as shown in FIG. 11, by inputting the password Be able to read and write.

[0031] Here, the password you entered is X, Y, Z.
If it does not match any of the above, it switches to RESET mode and reads the card ID, reads and writes the IC memory,
This mode does not allow you to do either of the following.

[0032] In this way, unless password It is possible to prevent data from being read and copy products being manufactured.

Furthermore, even if the data in the IC memory is read out by some method, if the main body has a function to identify the card ID, the main body will not operate unless the correct ID is output. Therefore, even if a copy product is manufactured, it can be prevented from operating on the main body.

Next, this second embodiment will be explained in detail with reference to FIGS. 6 to 9.

FIG. 6 is a block diagram showing the entire second embodiment, and FIGS. 7 to 9 are circuit diagrams showing FIG. 6 in more detail. In each of these figures, numerals 1 to 7 are the same as the elements described in the first embodiment, and in this embodiment, numerals 8 to 12 are newly added.

That is, between the IC memory card terminal and the IC memory 7, a control signal determination circuit 1, an address signal holding circuit 2, a data signal holding circuit 3, a data DX/
DY determination circuits 5, 8, address X/Y/Z determination circuit 4,
9, 10, an inverted CE output control circuit 6, an ID output control circuit 12, and an ID register 11.

Note that as the IC memory 7, a 256 kilobit OTPROM is used as in the first embodiment, and its memory map is as shown in FIG.

The operation mode regarding this IC memory 7 is as follows:
As shown in FIG. The difference between FIG. 12 and FIG. 5 (first embodiment) is that an "ID read" mode is newly added.

In FIGS. 6 to 9, A15 is an address signal for switching between the IC memory side and the dedicated control circuit side, and uses the highest address signal of the IC memory. When this A15 is "L", it is possible to access the IC memory 7, and when it is "H", it is possible to input a password, that is, to switch the operation mode and read the card ID.

Reference numeral 1 denotes a control signal determination circuit, which outputs an "L" level when a write command is input from the main body when A15 is at an "H" level. 2 and 3
is a holding circuit for address and data signals, and the signal from the control signal determination circuit 1 changes from "L" level to "
This circuit holds the address and data signals input at that time when the signal rises to the H'' level.

4, 9 and 5, 8 are address and data signal determination circuits, and only when the signals held in the address and data signal holding circuits 2 and 3 match passwords X and password Y, respectively. “H”
Output the level.

Reference numeral 10 denotes an address signal determination circuit, which outputs an "H" level only when the address signal from the main body matches the password Z.

6 is an inverted CE output control circuit; when the inputs from the judgment circuits 4 and 5 are at the "H" level, when the main body inputs the "L" level to A15 and the "L" level to the inverted CE; Then, the "L" level is supplied to the inverted CE input terminal of the IC memory 7 to put the IC memory 7 into an operating state and to make it readable and writable.

12 is an ID output control circuit, and when the inputs from the determination circuits 8 and 9 are at "H" level, the A1 output from the main body is
When the "H" level is input to 5 and the "L" level is input to the inverted CE, the "L" level is supplied to the inverted CE input terminal of the ID register 11 to enable the ID register 11 to output the ID, and the card ID is output. Make it readable. At this time, by inputting an "H" level from the address determination circuit 10 and an "L" level from the main body to the inverted OE, the card ID is output from the ID register 11.

[0045] Therefore, by inputting a specific signal serving as a password from the main body to the address bus and data bus, the operation mode can be switched and the card ID can be read.

Here, the password refers to data DX (or D
Indicates that the command to write Y) is input from the main unit, and Z
This means that a command to read data from a specific address Z is input from the main body (see FIG. 11).

That is, only by inputting a command to write the specific data DX to the specific address X, can the IC memory 7 be put into an operating state, and can the IC memory 7 be read and written. In this way, the data cannot be read out with a general-purpose reading device, so it is possible to prevent illegally manufactured copies.

[0048] Furthermore, only by inputting a command to write specific data DY to a specific address Y can the card ID be enabled for output.
D can now be read. Under this state, the card ID can be read by inputting a command to read data from the specific address Z.

Note that in the second embodiment described above, the inverted CE signal is controlled by a dedicated control circuit, but by controlling the inverted OE signal, only writing is possible before password X is input; It is also possible to realize an IC memory card that can also be read. If this is carried out using an inverted PGM signal, the IC will be able to read only before inputting password X, and can also write after inputting password
It is also possible to realize a memory card.

[0050]

As explained above, according to the present invention, the dedicated control circuit works to prevent the IC memory from becoming operational unless a predetermined password is input from the main unit. It is possible to prevent someone from reading the data and manufacturing a copy.

[0051] Furthermore, since the card ID cannot be read unless a specific password is entered from the main unit, even if a third party were to illegally read the data and manufacture a copy of the product. By adding a function to the main body to identify whether or not the correct card ID is output, it is possible to prevent a copy from operating on the main body, thereby eliminating the meaning of the product as a copy.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a detailed circuit diagram of the first embodiment.

FIG. 3 is a detailed circuit diagram of the first embodiment.

FIG. 4 is a diagram showing a memory map in the first embodiment (when the IC memory is a 256 kilobit OTPROM).

FIG. 5 is a diagram showing the operation mode of the IC memory in the first embodiment.

FIG. 6 is a block diagram showing a second embodiment of the present invention.

FIG. 7 is a detailed circuit diagram of a second embodiment.

FIG. 8 is a detailed circuit diagram of a second embodiment.

FIG. 9 is a detailed circuit diagram of the second embodiment.

FIG. 10 is a diagram showing a memory map in the second embodiment (when the IC memory is a 256 kilobit OTPROM).

FIG. 11 is a diagram showing operation modes in the second embodiment.

FIG. 12 is a diagram showing operation modes in the second embodiment.

FIG. 13 is an explanatory diagram of the prior art.

[Explanation of symbols]

1 Control signal judgment circuit 2 Address signal holding circuit 3 Data signal holding circuit 4 Address X judgment circuit 5 Data DX judgment circuit 6 Inverted CE output control circuit 7 IC memory 8 Data DY judgment circuit 9 Address Y judgment circuit 10 Address Z judgment circuit 11 ID register 12 ID output control circuit

Claims (2)

[Claims] Claim 1: In an IC memory card equipped with an IC memory that becomes operational when a control signal of a specific level is applied to a chip enable terminal, a plurality of control signals supplied from the main device side determine the input of a password. control signal determining means that outputs a determination signal of a predetermined level only when an instruction is given; and holding means that retains the address signal and data signal supplied from the main device side, respectively, in response to the output of the determination signal. password determining means for outputting a match signal when the signal held in the holding means matches a predetermined password; and a signal for instructing access to the IC memory after the match signal is output. 1. An IC memory card comprising memory control means for setting a chip enable terminal of the IC memory to a specific level to put the IC memory into an operating state when the IC memory is given from the main device side. 2. In an IC memory card equipped with an IC memory that becomes operational when a control signal of a specific level is applied to a chip enable terminal, a plurality of control signals supplied from the main device side determine the input of a password. control signal determining means that outputs a determination signal of a predetermined level only when an instruction is given; and holding means that retains the address signal and data signal supplied from the main device side, respectively, in response to the output of the determination signal. and a password determining means for outputting a matching signal for identifying the password when the signal held in the holding means matches one of the plurality of passwords, and a password determining means for storing specific card ID information. An IC memory card comprising: an ID register in which the ID register is stored; and control means that enables access to the IC memory or reading of the ID register depending on the type of the coincidence signal.