Storage Controller Runtime ZQ Calibration for UECC Recovery
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Solution Overview
Problem
High-capacity storage devices experience slowed operation speeds due to the execution of defense codes to correct uncorrectable error correction codes (UECC) caused by process-voltage-temperature (PVT) variations in the interfacing environment between the storage controller and non-volatile memory (NVM), which can arise from channel characteristics.
Innovation Solution
A storage device and controller system that performs runtime ZQ calibration to adjust impedance codes based on channel conditions, determining whether the NVM device is busy or not, and executing a defense code only when UECC does not originate from channel characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a defense code is executed to correct UECC errors, then data reliability is improved, but storage device operation speed deteriorates
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting impedance parameters through runtime ZQ calibration. The storage controller modifies impedance matching parameters based on detected channel conditions, thereby correcting UECC errors caused by impedance mismatch without requiring time-consuming defense code execution. This resolves the contradiction by changing the electrical parameters of the interface to prevent errors rather than correcting them later.
Solution Approach 2:
The patent implements preliminary action by performing runtime ZQ calibration proactively during device operation. Instead of waiting for UECC errors to occur and then executing defense codes, the system continuously monitors channel conditions and adjusts impedance parameters in advance, preventing UECC errors before they impact data reliability and maintaining high operation speed.
2Speed
If runtime ZQ calibration is performed, then impedance mismatch is reduced and operation speed is improved, but device complexity increases
Solution Approach 1:
The patent applies self-service by implementing automatic runtime ZQ calibration functionality within the storage controller itself. The controller autonomously monitors channel conditions, detects impedance mismatches causing UECC errors, and performs calibration adjustments without external intervention. This self-service approach reduces impedance mismatch and maintains high operation speed while avoiding the need for additional external calibration equipment or complex external control systems.
3Reliability
If runtime ZQ calibration is implemented, then data transmission quality is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies universality by designing the storage controller to perform multiple functions: data access operations, UECC error detection, channel condition monitoring, and runtime ZQ calibration. By integrating these diverse functions into a single controller unit, the system improves data transmission quality through adaptive impedance matching while avoiding the need for separate dedicated calibration hardware, thereby reducing manufacturing complexity.
Data Source
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AI summary
A storage device comprises a non-volatile memory (NVM) device configured to store data, and a storage controller configured to control the NVM device, in which the storage controller is further configured to send an access command to the NVM device to access data stored in the NVM device, receive first access data corresponding to the access command from the NVM device, perform error correction on the first access data, determine that the first access data is an uncorrectable error correction code (UECC), in response to the first access data being determined as being the UECC, determine that the NVM device is in a busy state, and send a runtime ZQ calibration command to the NVM device in response to the NVM device being determined as being in the busy state.