Semiconductor Memory Delay Compensation for High-Speed Synchronization
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Solution Overview
Problem
Semiconductor memory devices, particularly NAND-type flash memory, face challenges in synchronizing internal data transmission with external control signals due to internal latency, which becomes more difficult at higher clock frequencies and varying environmental conditions like temperature and voltage variations, hindering high-speed operation.
Innovation Solution
A semiconductor memory device comprising a data input device, delay estimation device, memory array, data output device, and timing adjustment device, where the delay estimation device estimates internal circuit delays and stores this information to adjust the output timing of the data output device, ensuring synchronization with external control signals despite environmental variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the clock frequency of external control signals is increased to achieve high-speed operation, then data transmission speed is improved, but synchronization with internal data transmission becomes more difficult due to internal delay variations
Solution Approach 1:
The delay estimation device performs preliminary estimation of internal circuit delay during the data input period (when commands and addresses are being latched), before the actual data transmission occurs. This preliminary delay information is stored and used to adjust timing in advance, enabling the system to maintain synchronization even at high clock frequencies where delay variations would otherwise cause desynchronization.
Solution Approach 2:
The system establishes a feedback loop where the delay estimation device continuously monitors internal circuit delay characteristics during operation, stores this information, and feeds it back to the timing adjustment device. The timing adjustment device then uses this feedback to dynamically adjust output timing, ensuring sustained synchronization reliability as clock frequency increases.
2Adaptability or versatility
If environmental conditions (temperature, voltage) vary, then operational flexibility is improved, but internal delay varies making synchronization difficult
Solution Approach 1:
The system transitions from a static timing approach to a dynamic one by continuously estimating delay during operation and adjusting timing based on real-time conditions. The delay estimation device captures delay characteristics under varying temperature and voltage conditions, and the timing adjustment device dynamically adapts output timing accordingly, maintaining synchronization reliability across different environmental conditions and operational flexibilities.
3Reliability
If delay compensation is implemented to maintain synchronization, then synchronization reliability is improved, but device complexity increases due to additional circuits
Solution Approach 1:
The delay estimation device is designed to serve multiple functions: it estimates delay during data input, stores the delay information, and provides this information for timing adjustment during data output. By making this single device multi-functional, the patent reduces the need for separate dedicated circuits for each function, thereby limiting the increase in device complexity while still achieving improved synchronization reliability.
Solution Approach 2:
The patent combines the delay estimation function with the existing data input and output timing control circuits. Rather than adding completely separate delay compensation circuits, the delay estimation is integrated into the existing operational flow, and the timing adjustment leverages the stored delay information within the existing control architecture, merging multiple functions into unified circuit operations.
Data Source
AI summary
A semiconductor memory device which is capable of high-speed operation in synchronization with external control signals is provided. The semiconductor memory device has a data input portion, a memory array, a data output portion, and a control portion. The data input portion receives command and address input data in response to the external control signals. The memory array has a plurality of memory elements. The data output portion outputs data read from the memory array in response to the external control signals. The control portion has the function of delay-compensation. During the time interval for receiving the input data, the function of delay-compensation estimates the delay time of the internal circuits, stores the estimated delay-time in a memory unit, and adjusts the output timing of the data output portion.