Memory Circuit Power Reduction via MTJ Write Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional SRAM memory circuits experience higher power consumption during active usage compared to when data is stored in a nonvolatile manner using ferromagnetic tunnel junction devices, leading to increased standby power consumption.
Innovation Solution
The implementation of a memory circuit that utilizes ferromagnetic tunnel junction devices in conjunction with bistable circuits and a control unit to determine whether data needs to be stored in these devices, reducing power consumption by minimizing current flow during data writing and storage, and optimizing power supply control to lower overall power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If data is stored in ferromagnetic tunnel junction devices in a nonvolatile manner, then standby power consumption is reduced, but power consumption during active usage increases
Solution Approach 1:
The memory system dynamically switches between volatile bistable circuit mode and nonvolatile ferromagnetic tunnel junction device mode based on operational requirements. During active usage, data remains in the low-power bistable circuit, while during standby, data is transferred to the ferromagnetic tunnel junction device, optimizing power consumption across different operational states
Solution Approach 2:
The control unit determines in advance whether data needs to be stored in the ferromagnetic tunnel junction device before initiating the storage operation. This preliminary determination prevents unnecessary write operations and associated power consumption by only activating the nonvolatile storage path when actually required
2Speed
If data is continuously maintained in bistable circuits, then fast access is achieved, but power consumption increases
Solution Approach 1:
The system dynamically manages data location between fast volatile bistable circuits and nonvolatile ferromagnetic tunnel junction devices. Frequently accessed data remains in the bistable circuit for rapid access, while less frequently accessed data is stored in the ferromagnetic tunnel junction device, creating a dynamic hierarchy that balances speed and power consumption
Solution Approach 2:
Data that does not require immediate access is extracted from the power-consuming bistable circuit and stored in the ferromagnetic tunnel junction device. This extraction reduces the burden on the bistable circuit and eliminates unnecessary power consumption while maintaining data availability when needed
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces power consumption by determining whether data needs to be stored in ferromagnetic tunnel junction devices, thereby minimizing power usage during both active and standby modes.
Implementation Method 1
data written in a bistable circuit of an SRAM (Static Ramdom Access Memory) is stored into a ferromagnetic tunnel junction device (MTJ) in a nonvolatile manner
Data Source
Figure 1A~1C
Figure 2
Figure 3
AI summary
A memory circuit includes: a ferromagnetic tunnel junction device, a readout circuit configured to read out data written into the ferromagnetic tunnel junction device in a nonvolatile manner, and a control unit configured not to write data to be written in a nonvolatile manner into the ferromagnetic tunnel junction device when an output of the readout circuit is the same as the data to be written into the ferromagnetic tunnel junction device in a nonvolatile manner, and configured to write the data to be written in a nonvolatile manner into the ferromagnetic tunnel junction device when the output of the readout circuit is not the same as the data to be written in a nonvolatile manner.