JPS58122150U

JPS58122150U - Unauthorized access detection circuit to memory

Info

Publication number: JPS58122150U
Application number: JP1679282U
Authority: JP
Inventors: 飯島　健滋
Original assignee: 三菱電機株式会社
Priority date: 1982-02-08
Filing date: 1982-02-08
Publication date: 1983-08-19

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

第１図は従来のメモリへの不正アクセス検出回路を示す
ブロック図、第２図は本考案によるメモリへの不正アク
セス検出回路を示すブロック図である。１・・・アクセスアドレス設定レジスータ、２・・・実
行中アクセスアドレスレジスタ、３・・・プログラム番
　　−号設定レジスタ、４・・・実行中プログラム番号
レジスタ、５Ａ〜５Ｎ・・・レジスタ値一致検出回路、
６、・・ＮＯＴ回路、７．１１・・・ＡＮＤ回路、８・
・・プログラムカウンタ、９０〜９Ｎ・・・プログラム
カウンタ値設定レジスタ、１０・・・ＮＯＲ回路、１２
・・・ＯＲ回路。なお、図中、同一符号は同−又は相当
部分を示す。FIG. 1 is a block diagram showing a conventional memory unauthorized access detection circuit, and FIG. 2 is a block diagram showing a memory unauthorized access detection circuit according to the present invention. 1...Access address setting register, 2...Access address register in progress, 3...Program number - number setting register, 4...Program number in progress register, 5A to 5N...Register value match detection circuit,
6....NOT circuit, 7.11...AND circuit, 8.
...Program counter, 90-9N...Program counter value setting register, 10...NOR circuit, 12
...OR circuit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims

[Scope of utility model registration request]

A first register value that inputs the values of an access address register during execution that stores an access address when a program is executed by a computer and an access address setting register that sets a predetermined access address and outputs an access address match detection signal. A second register value that inputs the values of the match detection circuit, the running program number register that stores the running program number, and the program number setting register that sets a predetermined program number, and outputs a program number matching detection signal. a coincidence detection circuit, and is configured to generate an interrupt signal when the memory is accessed in Taisho 7 based on the coincidence detection signal of the access address and the mismatch detection signal of the -program number. , a program counter that counts the execution of a program, each program counter value setting register that stores the program counter value when a legitimate access is made during legitimate program execution, and the program counter values of these registers and the above. Each register value match detection circuit inputs the value of the program counter and outputs a match detection signal, and the program counter when the stored program counter value and the executed program counter value do not match. At the same time as obtaining the logical sum output of the lower value match signal and the above program number match detection signal, the logical sum output of this AND output and the above program number match detection signal is obtained, and the logical sum output and the above program number match detection signal are obtained. 1. A circuit for detecting unauthorized access to a memory, comprising: a logic circuit that generates an interrupt signal at the time of unauthorized access to the memory by ANDing an access address with a match detection signal.