| 摘要 |
PURPOSE:To ensure the protection of the resources in a user state by inhibiting an access given to the specific resources in a state other than the one where a privilege state is switched to a special state. CONSTITUTION:A state holding means 3 is provided to hold both privilege and user states for the state information outputted from a microprocessor. While an inhibiting means 4 inhibits the communication of data when the microprocessor 2 and the means 3 are kept under a special state and a user state respectively. Then an access is inhibited to the specific resources 1 when the microprocessor 2 is switched to a special state from a user state. In such a constitution, no data is written into the resources and therefore the resources can be protected since the means 3 is holding a state signal showing that the microprocessor 2 is kept under a user state even through the microprocessor 2 is set in a specific state and tries to give an access to the inside of the resources with the actuation of a program applied while the microprocessor 2 is kept under a user state.
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