Semiconductor Impedance Calibration with Background Arbitration

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Solution Overview

Problem

As the number of semiconductor devices coupled to a shared external resistance for calibration increases, it becomes challenging to complete calibration operations within a specified time period, leading to potential impedance mismatches and data distortion, especially as operational speeds increase and signal swing widths decrease.

Innovation Solution

A calibration circuit that arbitrates amongst multiple semiconductor devices for use of the external resistance and performs calibration operations in the background, allowing for the storage and application of calibration parameters without relying on a memory controller command, enabling continuous operation and reducing total calibration time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple semiconductor devices share a common external resistance for calibration, then the quantity of devices increases, but the total calibration time exceeds the specified time period

Engineering Contradiction:

Improvenumber of devicesVSAvoidcalibration time

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The calibration circuit performs calibration operations in the background before a memory command is provided, rather than waiting for the command. This preliminary calibration ensures that when multiple devices need calibration, they can complete their calibration operations within the specified time period following the memory command, preventing the total calibration time from exceeding the allowed duration.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The calibration circuit enables continuous background calibration operations that do not interrupt normal device operation. By continuously performing calibration in the background and automatically applying parameters when calibration completes, the system maintains optimal impedance matching across multiple devices without requiring sequential calibration that would consume excessive time.

Inventive Principle:

Principle #20Continuity of useful action

2Reliability

If calibration operations are performed sequentially for multiple devices, then contention for the external resistance is avoided, but the total calibration time becomes impractically long

Engineering Contradiction:

Improvecalibration accuracyVSAvoidtotal calibration time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The calibration circuit automatically applies calibration parameters to the programmable termination components once calibration is complete, without requiring intervention from a memory controller. This self-service mechanism allows multiple devices to independently perform and complete calibration operations simultaneously, eliminating the need for sequential calibration while ensuring each device achieves accurate impedance matching.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

By performing calibration operations in advance before memory commands are issued, the system ensures that all calibration parameters are ready and applied before the specified time period following the memory command begins. This preliminary action allows multiple devices to complete calibration without exceeding time constraints while maintaining calibration accuracy.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If calibration parameters are applied only after a memory command is provided, then control is maintained, but calibration may not be completed within the specified time period

Engineering Contradiction:

Improvecalibration controlVSAvoidtime period for calibration

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The calibration circuit performs calibration operations in the background before a memory command is provided and automatically applies calibration parameters when calibration completes. This ensures calibration is finished within the specified time period following the memory command while maintaining operational control through the automatic application mechanism.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The calibration circuit monitors the completion of calibration operations and automatically triggers parameter application based on calibration status. This feedback mechanism ensures that calibration parameters are applied at the optimal moment - immediately when calibration completes - guaranteeing that control is maintained while calibration is completed within the required time framework.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10868519B2Apparatuses and methods for calibrating adjustable impedances of a semiconductor device

Publication Date: 2020.12.15 LODESTAR LICENSING GROUP LLC

AI summary

Apparatuses and methods for calibrating adjustable impedances of a semiconductor device are disclosed in the present application. An example apparatus includes a register configured to store impedance calibration information and further includes programmable termination resistances having a programmable impedance. The example apparatus further includes an impedance calibration circuit configured to perform a calibration operation to determine calibration parameters for setting the programmable impedance of the programmable termination resistances. The impedance calibration circuit is further configured to program the impedance calibration information in the register related to the calibration operation.