Non-Volatile Memory Refresh Interface for Automotive Power-Down
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-volatile memory devices experience unreliable data storage and retention when programmed at extreme temperatures, leading to read failures and data loss due to varying operating characteristics, especially in automotive systems where temperature fluctuations are significant.
Innovation Solution
An interface and low power mode are implemented in the host system to send refresh commands to the memory system after the automotive system powers down, allowing memory cells programmed at extreme temperatures to be refreshed as the system cools, using a host system controller to manage power and refresh operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-volatile memory is programmed at extreme temperatures, then data storage capacity is achieved, but data retention reliability deteriorates due to varying operating characteristics
Solution Approach 1:
The patent implements a preliminary refresh operation before the memory device is powered off at extreme temperatures. The controller detects when the device temperature exceeds a threshold and initiates a refresh of memory blocks before shutdown, ensuring data is rewritten under more favorable thermal conditions or at least while still accessible, thereby preventing data loss that would occur if refresh were delayed until after power-down
Solution Approach 2:
The system employs temperature sensing feedback to monitor the memory device temperature in real-time. When the temperature exceeds a predetermined threshold, this feedback triggers the controller to initiate refresh operations. This closed-loop control ensures refresh is performed at the appropriate moment based on actual thermal conditions, balancing the need to prevent data loss with the constraints of power availability
2Use of energy by moving object
If the automotive system powers down to save energy, then power consumption is reduced, but memory refresh operations cannot be performed leading to data loss
Solution Approach 1:
The patent performs the memory refresh operation preliminarily, before the power-down event occurs. The controller monitors system state and initiates refresh of memory blocks when the system is still powered but temperature has reached critical levels. This timing ensures refresh completes using available power before shutdown, preventing the need for post-power-down refresh that would be impossible without power
Solution Approach 2:
The system takes preliminary anti-action by preventing the harmful condition (data loss) before it can occur. By detecting extreme temperatures and triggering refresh before power-down, the system counteracts the potential data degradation that would result from programming or retaining data at extreme temperatures followed by power-loss, thereby preventing rather than correcting the problem
3Productivity
If memory cells are programmed at extreme temperatures, then storage operations are completed, but read failures occur due to operating characteristic variations
Solution Approach 1:
The patent implements a preliminary refresh operation that rewrites data in memory blocks before the system powers down. This refresh ensures that even if data was programmed at extreme temperatures with potential degradation, a fresh copy is written while the system is still operational, improving the likelihood of successful subsequent read operations when the system restarts
Solution Approach 2:
The system changes the operational parameters by monitoring temperature and dynamically adjusting the refresh strategy based on thermal conditions. When temperature exceeds thresholds, the system initiates refresh operations with modified timing and potentially different write parameters optimized for the thermal state, thereby compensating for the degraded operating characteristics at extreme temperatures
Data Source
AI summary
Methods, systems, and devices supporting an interface for refreshing non-volatile memory are described. In some examples, a host system may communicate with a memory system, where both the host system and the memory system may be included within a vehicle (e.g., an automotive system). The host system may receive an indication that the vehicle is powering down (e.g., shutting off an engine or lowering power output from a battery). The host system may switch from a first mode corresponding to a first power usage to a second mode corresponding to a second, lower power usage in response to the vehicle powering down, the second mode supporting initiation of a refresh operation at the memory device. The host system may transmit a refresh command to the memory system to refresh non-volatile memory while the vehicle is powered down if the host system is operating in the second mode of operation.