| 摘要 |
An integrated circuit, for use in a microprocessor-based chip card that provides several different functions at different hierarchical levels. The circuit has a microprocessor, a read-only memory managing a protection system and an EEPROM capable of containing not only data but also a code that can,be executed by the microprocessor. Different programs are placed in the EEPROM memory zones (Z1C, Z2C, Z3C). The read-only memory contains filtering instructions used to read a filter address in a specified zone Z1B, Z2B, Z3B of the EEPROM. Depending on the contents of this zone, the program will be routed, or not routed, towards the zones (Z1C, Z2C, Z3C). Thus information is recorded at only one address of the EEPROM in order to control accessibility to the different functions of the circuit.
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