Semiconductor Storage Device Idle Power Management

Solution Overview

Problem

Semiconductor storage devices face high power consumption during idle periods due to leakage currents, and frequent power-off to reduce consumption increases the time for host access and lowers the reliability of nonvolatile memory through increased rewriting in backup processing.

Innovation Solution

A semiconductor storage device with a memory controller, switch controller, and interpreter that temporarily moves management data to a backup memory during idle periods, allowing power to be turned off in parts of the device while maintaining data integrity and reducing power consumption by using a separate power supply domain for essential components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If power is turned off during idle period to reduce power consumption, then power consumption is reduced, but access time increases and nonvolatile memory reliability deteriorates due to frequent backup processing

Engineering Contradiction:

Improvepower consumptionVSAvoidaccess time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The memory system is divided into two independent domains: a first nonvolatile memory domain for storing management data and a second nonvolatile memory domain for storing user data. This segmentation allows the first memory to remain powered on during idle periods while the second memory can be powered off, resolving the contradiction by maintaining critical data availability without keeping the entire system powered on.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A buffer memory is introduced as an intermediary component between the host and the memory domains. The buffer memory caches management data and control information, allowing the system to maintain fast access times by serving data from the buffer during idle periods while the first nonvolatile memory remains powered on, without requiring frequent backup operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If power is turned off during idle period to reduce power consumption, then power consumption is reduced, but nonvolatile memory reliability deteriorates due to increased rewriting from backup processing

Engineering Contradiction:

Improvepower consumptionVSAvoidnonvolatile memory reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The memory system is divided into two independent domains: a first nonvolatile memory domain for storing management data and a second nonvolatile memory domain for storing user data. This segmentation allows the first memory to remain powered on during idle periods while the second memory can be powered off, resolving the contradiction by maintaining critical data availability without keeping the entire system powered on.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different power management strategies are applied to different parts of the memory system. The first nonvolatile memory domain maintains power supply during idle periods to preserve data without requiring backup operations, while the second nonvolatile memory domain undergoes power cycling. This local differentiation resolves the contradiction by applying power conservation only where appropriate without compromising overall system reliability.

Inventive Principle:

Principle #3Local quality

3Loss of time

If management data is continuously stored in memory to maintain fast access, then access time is reduced, but power consumption increases due to leakage current in non-operating state

Engineering Contradiction:

Improveaccess timeVSAvoidpower consumption

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The memory system is divided into two independent domains: a first nonvolatile memory domain for storing management data and a second nonvolatile memory domain for storing user data. This segmentation allows the first memory to remain powered on during idle periods while the second memory can be powered off, resolving the contradiction by maintaining critical data availability without keeping the entire system powered on.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system implements periodic power management where the switch controller periodically assesses whether to turn off power to the second memory domain based on activity patterns. During idle periods, power is turned off to reduce leakage current, while during active periods, power is restored for fast access. This periodic action resolves the contradiction by dynamically balancing power consumption and access time requirements.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS9032235B2Semiconductor storage device and method for controlling the semiconductor storage device

Publication Date: 2015.05.12 KIOXIA CORP

AI summary

According to one embodiment, a semiconductor storage device includes a nonvolatile memory, memory controller storing control information, a switch between the nonvolatile memory/memory controller and a power supply terminal, a second memory, an interpreter interprets a command, a switch controller, and a third memory stores an address of the control information in the second memory. The memory controller instructs the switch controller to open the switch after writing the control information into the second memory and reads the control information from the second memory based on the address stored in the third memory when the memory controller is electrically connected to the first power supply terminal.