Title:
METHOD AND APPARATUS FOR CONTROLLING ACCESS TO MEMORY
Document Type and Number:
Japanese Patent JPS6210745
Kind Code:
A
Abstract:
A method for controlling memory access to a user area and an initial code area of a main memory of a chip card includes carrying out an internal release procedure with a data comparison of an initial code from the initial code area and a data word from a terminal; firmly coupling addresses of the main memory and of a control memory to each other; marking several storage locations of the main memory as the initial code area with one control bit at a time in the control memory; marking a first code deposited in the associated storage location of the first code area as activated or deactivated with one further control bit at a time in the control memory; generating an initial release signal in a release procedure only if a storage location is addressed by an activated initial code and if agreement with the data word entered by the terminal prevails; and preventing generation of the initial release signal if a deactivated code word is addressed and/or if the respective first code does not agree with the data word, and an apparatus for carrying out the method.
Inventors:
HARUTOMUUTO SHIYURENKU
Application Number:
JP15591586A
Publication Date:
January 19, 1987
Filing Date:
July 02, 1986
Export Citation:
Assignee:
SIEMENS AG
International Classes:
B42D15/10; G06F12/14; G06F21/60; G06K17/00; G06F21/62; G07F7/10; (IPC1-7): B42D15/02; G06F12/14; G06K17/00
Attorney, Agent or Firm:
Tomimura Kiyoshi
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