Multi-Rank Termination Resistance Calibration for Write Signal Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor devices face challenges in efficiently calibrating termination resistance across multiple ranks, which affects signal integrity and performance, especially during write operations.
Innovation Solution
A semiconductor system is designed with a controller that transmits specific command addresses and chip selection signals to enable each rank to calibrate its termination resistance independently. The first rank calibrates its resistance to a target resistance during write operations, while the second rank adjusts its resistance dynamically based on the received signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single termination resistance calibration method is used for all ranks, then the device complexity is reduced, but the signal integrity and performance of individual ranks deteriorate
Solution Approach 1:
The patent divides the calibration control into separate chip selection signals (first chip selection signal for first rank, second chip selection signal for second rank). This segmentation allows each rank to be calibrated independently with appropriate termination resistance values, improving signal integrity for each rank while maintaining manageable complexity through structured control.
Solution Approach 2:
The patent applies different termination resistance calibration strategies to different ranks based on their specific operational requirements. The first rank uses target resistance calibration while the second rank uses dynamic resistance calibration, allowing each rank to have optimized local characteristics for its specific use case.
2Reliability
If termination resistance is dynamically adjusted for each rank, then the signal integrity improves, but the device complexity increases
Solution Approach 1:
The patent uses a unified command address structure and calibration framework that works across multiple ranks. The controller transmits calibration commands using the same basic protocol for all ranks, and the semiconductor device uses a universal calibration mechanism that responds to chip selection signals, reducing the overall complexity despite per-rank customization.
Solution Approach 2:
The patent performs termination resistance calibration before normal operational commands are executed. By pre-calibrating each rank's termination resistance based on its specific requirements, the system establishes optimal signal conditions in advance, avoiding the need for complex real-time adjustments during operation.
3Measurement precision
If calibration is performed for all ranks simultaneously, then the calibration precision is improved, but the power consumption increases
Solution Approach 1:
The patent implements calibration in periodic phases corresponding to different operational modes. During write operations, the first rank is calibrated with target resistance while the second rank uses dynamic resistance. During read operations, the calibration requirements differ. This periodic calibration approach ensures precision when needed while conserving power during non-calibration periods.
Solution Approach 2:
The patent dynamically adjusts the calibration state of different ranks based on their current operational mode. The second rank specifically uses dynamic resistance calibration that changes based on operational conditions, allowing the system to maintain calibration precision adaptively while minimizing power consumption by only activating calibration circuits when and where needed.
Data Source
AI summary
A semiconductor system includes a controller configured to apply a command address, a first chip selection signal, and a second chip selection signal, and a semiconductor device including a first rank and a second rank configured to calibrate each termination resistance, based on the command address, the first chip selection signal, and the second chip selection signal.