JPH11175404A - Address controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an address controller as a converting device of an address access signal for the security of an outside memory. SOLUTION: This device is provided with an address switch part 5 in which switching capable of arbitrarily changing the connection setting is performed in the stage of connecting an address access signal from a host system 1 with the address access signal of an outside memory 3. Also, security is maintained by making the memory mapping of the outside memory 3 different from mapping viewed from the host system and the host system secures the substantial connection setting by ID management.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an access circuit for a memory, and more particularly to an address controller for converting an address signal for security of data written in the memory.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram of a conventional example for address signal conversion.

According to this example, the address bus and the data bus of the CPU 20 are connected to the converter 21.
The conversion unit 21 and the external memory 22 are also connected to an address bus and a data bus.

In the external memory 22, an address conversion table of an address signal from the host system is written.

[0005] Before accessing the external memory 22, the CPU 20 reads address data of an address conversion table written in the external memory 22 from a specific address specified by the conversion unit 21. The read address data is automatically written to the memory in the conversion unit 21, and the data of the conversion address corresponding one-to-one to the address accessible by the CPU 20 is written.

When the CPU 20 accesses the external memory 22, an address is set to the external memory 22 via a conversion address table of the conversion unit 21.

[0007]

A first problem is that data in a memory can be easily read. The reason is,
This is because the address mapping of the memory and the address mapping of the host system are uniquely determined.

It is an object of the present invention to provide an address controller for improving the security of data in a memory by using means for making the mapping of data written in the memory different from the mapping viewed from the host system.

[0009]

An address controller according to the present invention receives a plurality of address access signals from a host system to an external memory, inputs all of the address access signals, and outputs the signals individually to an external memory. It has a plurality of address switches for each memory address access signal, and has a switch section for setting and connecting each address switch according to the setting signal of the host system, and the setting connection of the plurality of address switches can be arbitrarily changed at any time Is configured.

That is, the host system 1 has address switch units 6 to 7 which can change the connection of the address. The address switches 6 to 7 are accessible from the host system 1 and can be accessed by the host system 1.
The connection of the address arbitrarily determined on the side becomes possible.

The host system 1 has an ID management area and an address switch setting information area, and has means for managing address connection setting contents.

[0012]

FIG. 1 is a system configuration diagram of a first embodiment when an address controller 2 of the present invention is used.

FIG. 2 is a detailed block diagram of the address controller 2 shown in FIG.

FIG. 3 shows the address switch unit 5 shown in FIG.
FIG. 2 is a connection diagram of the internal configuration of FIG.

FIG. 4 is a conceptual diagram of connection of signals inside the address switches 6 and 7 shown in FIG.

FIG. 5 shows the address controller 2 of the present invention.
5 is an example of an address mapping when the external memory 3 in the host system is used when the address is used.

Detailed description of FIGS. 1, 2, 3 and 4 is as follows.

FIG. 1 is a diagram showing a configuration example of a system.
The address controller 2 outputs a plurality of address signals AD _{0 to} AD _n (hereinafter A) which are output from the host system 1.
D *) is used to receive the signal, change the address allocation, and change the corresponding CAD ₀ to CAD
_n (hereinafter referred to as CAD *) is output to the memory unit 3 as a signal.

FIG. 2 is an internal block diagram of the address controller. The decoder 4 controls the address switch 5 by a control signal ADCS ₀ enabling data access.
ＡＤ ADCS _n (hereinafter referred to as ADCS *) signal.

The address switch unit 5 is a host system 1
The connection of the CAD * signal, which is the address signal of the memory unit 3, to the AD * signal, which is the address signal input from the host system 1, is set by the write data from.

FIG. 3 is a diagram showing the internal configuration of the address switch section 5. In the address switch unit 5 shown in FIG. 3, the number of address signals is 20.

The address switching unit 5 is composed of 20 up to address the switch 6 ₀ to address switch 6 _19. The internal circuit configuration of each of the address switches 6 _{0 to} 6 ₁₉ is the same.

[0023] FIG. 4 is a connection schematic diagram of an address to be performed within the address switch 6 _{0-6 19.} Has twenty switches 8 _{0-8 19} each address switch for example, an address switch 6 in _0, the switch 8 ₀ host system 1
An address input signal from the AD ₀ signal, AD ₁ signal,
AD ₂ signal, ..., and AD ₀ signal in response to an instruction from the host system from the AD ₁₉ signals connected to A ₀ signal is an address input signal to the memory unit 3, also switch 8 ₁₉ from host system Connect the indicated AD ₁₉ signal to the A ₀ signal.

[0024] In Figure 4, the switch ₈₂ is in an on state, AD ₂ signal and the A ₀ signal is connected. That is,
The AD ₂ signal from the host system 1 is transmitted to A _{0 of the} memory unit 3.
The signal is converted and output by the address controller 2 as a signal.

FIG. 4 switch 8 ₀ conceptual diagram showing the switch 8 _1, switch _82, ..., the switch 8 _19, respectively, as input AD _0, AD _1, AD _2, ... AD ₁₉ ,
It is an electrical switch, not a mechanical switch. For example, an electronic switch or a rewritable E
The present invention may be realized by employing an EPROM cell.

Next, the operation of the present invention will be described.

First, the connection procedure of each address shown in the concept of connection of addresses shown in FIG. 4 will be described.

As shown in FIG. 10, the host system 1
It is to the address switch 6 ₀ to address switch 6 ₁₉ which is set to connect to a particular address space, to implement the connection address. For example, as shown in FIG.
If the _two signals you want to convert into A ₀ signal, to the address switch 60 via DB0~7 signal is a data bus signal may be set to "02h".

Each of the address switches 6 _{0 to} 6 ₁₉ has a binary / bit converter 50 and 20 switches.
Each switch _{8 0 ~8 19, AD 0 ~AD} 19 is connected individually to correspond, also be binary / bit conversion unit by bits converted BIT ₀ ~BIT ₁₉ also turn individually connected by 50 And the specified connection is made.

[0030] Thus, if you want to connect AD ₀ signal to the A ₁₉ signal, the data bus signal table shown in FIG. 14, to the address switch 6 ₁₉ may be set to "00h".

That is, if "1" is a desired position,
Since AD ₂ is a third position, set "02h" to binary / bit conversion unit 50, as the output of the binary / bit conversion unit 50, "BIT ₀ BIT ₁ BI
T ₂・ ・ ・ BIT ₁₈ BIT ₁₉ ”
.. 0 0 ”is output.

Since AD ₀ is the first position, “00h” is set in the binary / bit converter 50,
As the output of the binary / bit conversion unit 50, "BIT
₀ BIT ₁ BIT ₃ ... BIT ₁₈ BIT ₁₉ ”corresponds to“ 1 0 0.
0 "is output.

As described above, the AD ₀ signal, the AD ₁ signal,
..., AD ₁₉ signal, A ₀ signal, A ₁ signal, ..., A ₁₉
The signal is connected and converted one-to-one. As a result, the host system 1 recognizes the connection state of the address switch by plotting it in the address switch setting information area, and the configuration of the memory space accessed by the memory unit 3 can be completely different.

Although the correspondence of the data of each address is one-to-one, the memory unit 3 can realize the correspondence of the different addresses by each connection setting of the address connection of the address switch unit 5.

As described above, each address connection can be made by changing the connection of the internal switch of the address switch section 5. A method of managing the change of connection will be described.

FIG. 5 shows an example of a memory map set in the external memory 3. The memory map includes an ID management area of 4 bytes and a user memory area. Provide.
The ID management area is 4 bytes, and the address is FFFFC
To FFFFF.

The specific structure of the ID management area is as follows. In the example of FIG. 5 (details are shown in FIG. 6), the ID management area is composed of 3-byte ID data and 1-byte check bit.

FIG. 13 is a management map possessed by the host system, and the ID management area includes the ID map shown in FIG.
The content is the same as that of the management area. Further, an address switch 5 setting information area is provided, and connection setting information of each address switch is mapped.

In the host system 1, the address signal connection information of the address switch section 5 is managed by the above management map.
They are managed inside the host system 1 on a one-to-one basis.

Next, an actual memory access flow will be described.

The host system 1 first sets an address for the address switches 6 _{0 to} 6 _{19 of the} address switch unit 5 set in a specific address space. As described above, the switch 8 _0-8 shown in FIG. 4
Set by specifying bits for ₁₉ . For example, if you want to connect AD ₀ signal to the A ₁₀ signal, through the DB0~7 signal is a data bus signal, for setting that bit to "1" of the corresponding. In this case, the host system 1 to the address switch 6 ₁₀ address switch section 5 "0Ah",
And data setting.

The host system 1 executes A
For AD ₁₉ signals from the D ₀ signal, the address switch 6 ₀
From up to the address switch 6 _19, performs the connection setting of the address.

The host system 1 determines a 3-byte ID for the contents of the address connection setting. 3-byte ID
, A check bit is generated. Host system 1
Are addresses “FFFFFh” to “FFFFc” in the user memory map of the external memory 3 viewed from the host system 1.
A 3-byte ID and a 1-byte check bit are written at address "h". There is a one-to-one correspondence between the connection setting content of the address and the ID. The connection content of the address and the corresponding ID are the host system 1 side. Managed and stored.

Although the memory unit 3 is fixedly described in the system connection example of FIG. 1, the memory unit 3 may be a memory separable from the host system 1. In this case, the host system 1 manages and stores the address connection setting contents and IDs for the plurality of memory units 3.

Next, a flow when the host system 1 reads data from the memory unit 3 will be described.

The host system 1 manages and stores the ID.
, The address connection of the address switch unit 5 is performed.

The host system 1 reads the ID management area from the address “FFFFFh” to the address “FFFFch”, and uses the ID management map shown in FIG.
It is checked whether D and the 1-bit check bit match the data stored in the host system 1.
If they match, subsequent access to the memory unit 3 is guaranteed.

When a plurality of memory units 3 exist, the ID stored in the host system 1 and the memory unit 3 are stored in the same procedure.
The process is executed until the ID read from the ID matches.

FIG. 7 shows an example in which the memory unit 3 is incorporated in the host system 1. In this case, since the memory unit 3 is removed from the host system 1 and the data of only the memory unit 3 is read out in order from the address arrangement of the memory unit 3 and does not become the original data string, there is a data security effect.

FIG. 8 shows an example in which the memory unit 3 includes a plurality of memory units 13 and 14. As shown in FIG. 13, the host system 1 manages the IDs and address connection settings for the memory units 13 and 14. The memory unit 13 and the memory unit 14 can be connected to the host system 1 via a connector or the like. The host system 1 is connected to the memory unit 13 and the memory unit 1
It is checked whether or not the IDs of 4 match, and each can be accessed.

In the example shown in FIG. 8, the memory unit 13 and the memory unit 14 are assumed to be portable memory cards. Since the memory unit 13 and the memory unit 14 cannot be restored to the original data sequence except by the host system having the same information as the ID and the address connection setting contents managed and stored in the host system 1, 13. There is a security effect on the data in the memory unit 14.

[0052]

The first effect is that there is a security effect on data in the memory by arbitrarily changing the address connection at any time. The reason is that address connection information and ID management are executed by the host, and address connection switching is arbitrarily performed from the host as needed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a concept of a memory access circuit using an address controller of the present invention.

FIG. 2 is a block diagram of a first embodiment of the address controller of the present invention.

FIG. 3 is a detailed block diagram of an address switch unit 5 shown in FIG.

FIG. 4 is a detailed view of the address switch shown in FIG. 3;

FIG. 5 is an example of address mapping as viewed from the system when using the address controller of the present invention.

6 is a conceptual diagram of an ID management area shown in FIG.

FIG. 7 is a block diagram of a second embodiment of the memory access circuit including the address control according to the present invention.

FIG. 8 is a block diagram of a third embodiment of the memory access circuit including the address controller of the present invention.

FIG. 9 is a system conceptual diagram of a conventional external memory address access device.

10 is a block diagram of an address switch 6 ₀ shown in FIG.

11 is a diagram showing an operating state of the switch ₈₂ in the address switch 6 ₀ shown in FIG. 10.

FIG. 12 is a diagram showing a configuration of an ID management map of the host system 1.

FIG. 13 is a view illustrating a configuration of an ID management map for managing the external memories 13 and 14 of the host system.

FIG. 14 is a table showing BIT conversion of a data bus signal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host system 2 Address controller 3 Memory part 4 Decoder 5 Address switch part 6 Address switch 7 Address switch 8 Switch 9 Switch 10 Switch 11 Switch 12 Host system 13 Memory part 14 Memory part

Claims (6)

[Claims] When an external memory is accessed from a host system, an address controller, which is a means for converting a signal for accessing an address in the external memory for security of the memory, transmits an address signal from the host system to the external memory. An address controller comprising: a conversion connection setting unit that can arbitrarily set a conversion connection to a unique address access signal in a memory at any time. 2. The method according to claim 1, wherein the conversion connection setting means receives a plurality of address signals from a host system and outputs an individual address signal to a unique address of an external memory. 2. The address controller according to claim 1, comprising a switch. 3. The address controller according to claim 2, wherein said switch is an electronic switch. 4. The address controller according to claim 2, wherein said switch is an EEPROM. 5. The address controller according to claim 1, further comprising means for instructing the address switch by a binary code via a data bus from the host system to set the conversion connection setting means. 6. An external memory access management means comprising an ID management area indicating an address signal conversion connection setting means setting result and an address switch setting information area, and constantly managing connection in correspondence with address connection information. The address controller according to claim 1, further comprising: