DRAM Input Sampling Circuit for Invalid C/A Signal Masking

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In DRAM DIMM systems, the sharing of a C/A data bus among multiple DRAMs leads to unnecessary energy consumption due to the sampling of invalid C/A signals, causing level state fluctuations and excessive power usage.

Innovation Solution

An input sampling method and circuit that performs logical operations on the CS_n and C/A signals to determine a to-be-sampled signal, shielding the invalid part of the C/A signal, thereby preventing level state fluctuations and reducing energy consumption by only sampling valid signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the C/A data bus is shared among multiple DRAMs, then the device complexity is reduced and adaptability is improved, but unnecessary energy consumption increases due to sampling of invalid C/A signals

Engineering Contradiction:

ImproveC/A data bus sharing capabilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by performing logical operation between CS_n and C/A signals before the sampling process. The logical operator processes the signals in advance to generate a to-be-sampled signal that already has invalid parts shielded, so that the sampling circuit only samples valid signals, preventing unnecessary energy consumption from sampling invalid signals.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a logical operator as an intermediary component between the signal input and sampling circuit. This intermediary performs logical operation on CS_n and C/A signals to generate a to-be-sampled signal, acting as a mediator that filters out invalid signal portions before they reach the sampling stage, thereby reducing power consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If sampling is performed on all C/A signals, then measurement precision is maintained, but energy wastage increases due to sampling of invalid signals

Engineering Contradiction:

Improvesignal sampling accuracyVSAvoidenergy wastage

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

The logical operation is performed in advance before sampling to shield invalid parts of C/A signals. This preliminary action ensures that only valid signal portions are passed to the sampling circuit, maintaining measurement precision for valid signals while avoiding energy wastage from sampling invalid signals.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies partial action by selectively sampling only the valid portions of C/A signals rather than all signals. The logical operator shields invalid parts, so the sampling circuit performs sampling action only on necessary valid signal portions, reducing energy wastage while maintaining required measurement precision.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11978502B2Input sampling method, input sampling circuit and semiconductor memory

Publication Date: 2024.05.07 CHANGXIN MEMORY TECH INC

AI summary

An input sampling method includes the following operations. A first pulse signal and a second pulse signal are received. Logical operation is performed on the first pulse signal and the second pulse signal to determine a to-be-sampled signal. The to-be-sampled signal is obtained by shielding an invalid part of the second pulse signal according to a logical operation result. Sampling process is performed on the to-be-sampled signal to obtain a target sampled signal.