Enable Signal Generation Circuit Guard Key Verification
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Solution Overview
Problem
Current semiconductor apparatuses face challenges in generating an enable signal that effectively enables or disables internal circuits for specific operations, particularly in synchronizing with clock signals and command signals, while ensuring security through guard key mechanisms.
Innovation Solution
The semiconductor apparatus includes a command decoding circuit, seed signal generation circuit, guard key generation circuit, guard key reset circuit, guard key access control circuit, and enable signal output circuit, which generate and manage guard keys to prevent enable signal generation when guard keys are not sequentially enabled, ensuring secure operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a guard key mechanism is implemented to ensure security in enable signal generation, then security is improved, but device complexity increases due to additional circuits
Solution Approach 1:
The enable signal generation is divided into multiple stages with sequential guard key verification. The command decoding circuit generates operation codes that are verified against multiple guard keys (first guard key, second guard key, etc.) in sequence before the final enable signal is generated. This segmentation of the verification process enhances security while organizing the complexity into manageable modular stages.
Solution Approach 2:
The guard keys are verified in advance before the enable signal is generated. The command decoding circuit performs preliminary decoding of operation codes and validates them against guard keys before allowing the enable signal generation to proceed. This preliminary verification ensures security requirements are met before the critical enable signal is activated.
2Reliability
If multiple guard keys are sequentially verified to prevent unintended circuit activation, then reliability is improved, but operation time increases
Solution Approach 1:
The guard key verification process operates periodically with each command signal received. The command decoding circuit is triggered by clock signals and processes operation codes in a periodic manner, verifying guard keys at each cycle. This periodic operation allows systematic verification without continuous time consumption, maintaining efficiency while ensuring reliability.
3Measurement precision
If guard key access control is implemented to synchronize enable signal generation with clock and command signals, then synchronization accuracy is improved, but device complexity increases
Solution Approach 1:
The command decoding circuit serves multiple functions: it decodes operation codes from command signals, generates seed signals, verifies multiple guard keys sequentially, and controls enable signal generation. By making this single circuit multi-functional, the patent achieves precise synchronization with clock and command signals while avoiding the need for separate dedicated circuits for each function, thus limiting the increase in device complexity.
Data Source
AI summary
A semiconductor apparatus includes a command decoding circuit and an enable signal generation circuit. The command decoding circuit generates an operation code and a strobe pulse based on a command signal and a clock signal. The enable signal generation circuit generates a seed signal based on the operation code and the strobe pulse and generates an enable signal by shifting the seed signal. The enable signal generation circuit generates a plurality of guard keys based on a plurality of operation codes and the strobe pulse and prevents the generation of the enable signal for a predetermined time when the plurality of guard keys are not sequentially enabled.