JPH03113898A - Fixed storage device - Google Patents

Abstract

PURPOSE:To enable the regulation control for readout requirement in a specific region by storing the address information as a key inputted from outside in the previously arbitrarily decided sequence for the specific region, then allowing the succeeding address to be the address executing the regulation control for the readout requirement. CONSTITUTION:An electrically writable memory cell 10 constituted of 2<m> word X1 bit in provided and plural pieces of address information are inputted as the key in the previously arbitrarily decided sequence, and the input is stored at a key register 20. Next in the region of the address form (n+1) to (2<m>-1) of successively inputted memory cell 10, the arbitrary plural group of address having data are stored at the key register 20 as the address to regulate the readout. And for the readout requirement to the address of the memory cell 10 in the region, after receiving the address information inputting in the order of the memory contents are readout. In such a manner, in the region of the address from (n+1) to (2<m>-1) the regulation control for the readout requirement of the memory cell is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fixed memory device, and more particularly to a fixed memory device that performs regulatory control on read requests to memory cells within a specific area.

[Conventional technology]

In conventional fixed storage devices, it was possible to read the contents of any address in the entire area at any time.

[Problem to be solved by the invention]

The above-mentioned conventional fixed storage device has the problem that the contents of the entire area at any address can be read out at any time, so that the written storage contents cannot be kept confidential.

An object of the present invention is to store address information input from the outside in a predetermined order as a key in response to a read request to an arbitrary address within a specific area, and to read data stored at the next address. It is an object of the present invention to provide a fixed storage device that can be used as a key for regulating and controlling read requests.

[Means to solve the problem]

The fixed storage device of the present invention has 2 m words x 1 bits) - (m
and l is a natural number), address information input from the outside in an arbitrary predetermined order is stored as a key, and from address n+1 of the next memory cell of the fixed memory device. 2"-1 (n is a natural number satisfying 0 < n < 2m-1), a key register having a function to be used as a key for regulating reading of data stored at an arbitrary address within the area is provided, In response to a read request to an address of a memory cell in the area from address n+1 to 2-1 of the memory cell, address information stored in the key register and input in the predetermined order is received. The configuration is such that the stored contents at the specified address are read out.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

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

The fixed memory device 1 has an electrically writable memory cell 10 having a configuration of 2 m words x l bits, and has signal lines 100 to l bits.
It receives an m-bit address designation through OO+ (m-1), and inputs and outputs l-bit data through data input/output lines 300 to 300+ (1-1). Signal line 100~100+<
m-1), together with the memory cell 10, stores address information input in an arbitrary predetermined order as a key, and is used to control reading of data stored at an arbitrary address in the next area. A key register 20 having a function of being used as a key register and a read gate control unit 30 that controls a read gate 40 are connected.

The key register 20 is connected to a key register write control line 200 that inputs a signal to control writing, and to an access permission signal line 201 that outputs a signal that allows the read gate control unit 30 to access a specific area. There is. The read gate control section 30 has a read gate control signal line 202 that outputs a signal for controlling the read gate 40.

The memory cell 10 has data input/output lines 300 to 300+<1
-1) is connected to the program control line 203 that receives the control signal for writing the data received. Next, the operation will be explained.

When writing data to the memory cell 10, the signal lines 100-
The data given by the data input/output lines 300 to 300+ (1-1) is written to the address selected by 100-100-)-(by inputting a control signal from the program control line 203.

When restricting data reading, first the signal line 10
A plurality of address information from 0 to 100+(m-1) is input as a key in an arbitrary predetermined order. This input is stored in the key register 20. Next, a plurality of sets of arbitrary addresses having data in the area from address n+1 to 2m-1 of the memory cells that are successively inputted are used as addresses for regulating readout from now on, and are controlled by the key register write control line 200. It is stored in the key register 20 below.

In this state, the read gate control unit 3o controls the signal line 100
~100+(m-1) selected addresses are monitored,
If the detected address satisfies 0≦≦n (where n is a predetermined address value and satisfies the relationship n<2'''-1), the read gate 4o is enabled. do.

Furthermore, if the address is within the range from n+1≦ to ≦2−-1, the read gate control signal line 202 is set to “true” only when the access permission signal line 201 is “true”, and the readout is performed. Enable gate 4o.

A plurality of address information stored in a predetermined order in the key register 20 and a plurality of sets of arbitrary addresses in the area from address n+1 to 2w''-1 are erased even when the power to the device is turned off. The function will be restored again by turning on the power.

To read the stored contents from an arbitrary address that restricts reading from the outside, first input multiple address information stored in an arbitrary predetermined order, and then specify the address that restricts reading. , upon receiving this signal, the key register 20 outputs a “true” signal to the access permission signal line 201 to permit access to the specific area. Upon receiving this "true", the read gate control section 30 sets the read gate control signal line 202 to "true" and reads the stored content from the read gate 40.

Note that receiving l#JlIF for storing a plurality of address information in the key register 20 in an arbitrary predetermined order and a plurality of address information stored in an arbitrarily predetermined order,
After that, a program that performs read control by receiving an address that restricts reading is configured such that the address is 0≦≦
It can be stored in an area within a range of n.

〔Effect of the invention〕

As explained above, in response to a read request to an arbitrary address within a specific area, the present invention stores address information input from the outside in a predetermined order as a key, and reads the next address. , there is an effect that the address can be used as an address to perform regulatory control on read requests.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. 1...Fixed storage device, 10...Storage cell, 20...Key register, 30...
Readout gate control unit, 40--readout gate,
100~100+ <m=1)...Signal line, 2
00...-Key register write M control line, 201.
...Access permission signal line, 202...-Read gate control signal line, 203...Program control line, 300~300+ (1-1)...Data input output line.

Claims (1)

[Claims] In an electrically writable fixed storage device having a configuration of 2^m words x l bits (m and l are natural numbers), address information inputted from the outside in an arbitrary predetermined order is stored as a key, and the next fixed address information is stored as a key. Addresses n+1 to 2^m-1 of memory cells of the memory device (n is 0<n<2^m
A key register is provided which has a function to be used as a key for regulating the reading of data stored at an arbitrary address in the area (a natural number satisfying -1), and the key register is used as a key to regulate the reading of data stored at an arbitrary address in the area (a natural number satisfying -1), and the key register is used to control the readout of data stored at an arbitrary address in the area (a natural number satisfying -1). In response to a read request to an address of a memory cell in the area, after receiving the address information stored in the key register and inputted in the predetermined order, the stored contents of the specified address are read out. A fixed storage device characterized by: