IC Card State Management via DESELECT Command Handling

The patent applies preliminary action by storing the current OS state and application state into storage sections before the card transitions to the inactive state upon receiving a DESELECT command. This ensures that when the card is reactivated, the previously stored state information is already available for restoration, preventing loss of processing context while still allowing energy-saving deactivation

The patent changes the parameter of state management by introducing RFU1 and RFU2 bits that control whether to maintain or restore OS and application states. This parameter change mechanism allows flexible control over state transitions, enabling the card to either preserve or reset processing states based on the specific DESELECT command received, thus resolving the contradiction between energy saving and information retention

The patent applies universality by making the existing DESELECT command protocol serve multiple functions: it can trigger complete resets, temporary interruptions, or selective state restoration depending on the values of RFU1 and RFU2 bits. This multi-functionality approach allows the same protocol structure to handle various state management scenarios without increasing overall protocol complexity, while significantly improving adaptability

The patent segments the state management control into distinct components by separating OS state control (via RFU1 bit) and application state control (via RFU2 bit). This segmentation allows independent control over different state layers, enabling fine-grained state management where only necessary states are restored or maintained, thus providing versatility without proportionally increasing protocol complexity