Semiconductor Device Delay Calibration for Stacked Memory Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In three-dimensional semiconductor memory devices, process variations among stacked memory chips lead to differences in delay values, causing inconsistent operation timing and potential issues like insufficient margins and speed drops due to varying delay characteristics.
Innovation Solution
A semiconductor device with calibration circuits and delay control circuits that generate calibration codes to compensate for delay value differences among transfer paths, ensuring synchronized data output across stacked chips by adjusting internal strobe signals based on these codes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple stacked memory chips are used to increase capacity, then storage capacity is improved, but delay value differences among chips cause operation timing inconsistency and performance degradation
Solution Approach 1:
The patent performs delay calibration in advance during the initialization phase. The calibration circuit measures the delay values of all transfer paths before normal operation begins, generates calibration codes based on these measurements, and stores them for subsequent use. This preliminary action ensures that timing inconsistencies are compensated before they affect actual data operations, resolving the contradiction between using multiple chips for increased capacity while maintaining operation timing consistency.
Solution Approach 2:
The patent implements a feedback mechanism where the calibration circuit continuously monitors delay values of transfer paths and adjusts calibration codes accordingly. The delay control circuits use these calibration codes to dynamically adjust their delay amounts, creating a closed-loop system that compensates for process variations. This feedback approach maintains operation timing consistency across multiple stacked chips despite manufacturing variations.
2Reliability
If delay calibration circuits are added to compensate for process variations, then operation timing consistency is improved, but device complexity increases
Solution Approach 1:
The patent combines the calibration circuit and delay control circuits into an integrated timing synchronization system. The calibration circuit shares resources with the normal operation circuits, and the delay control circuits are merged with the existing transfer path structures. This merging approach reduces the overall device complexity while still achieving operation timing consistency across multiple stacked chips.
Solution Approach 2:
The patent changes the delay parameter of each transfer path based on calibration measurements. Instead of adding complex physical structures, the solution adjusts the electrical delay parameter through controllable delay elements that can be programmed with calibration codes. This parameter-based approach achieves timing synchronization with minimal additional circuit complexity.
3Measurement precision
If calibration codes are generated and stored for each chip, then delay compensation accuracy is improved, but manufacturing precision requirements increase
Solution Approach 1:
The calibration circuit performs self-calibration by automatically measuring its own transfer path delay values and generating appropriate calibration codes without requiring external precision equipment. Each chip independently characterizes its own timing characteristics during initialization, which reduces the manufacturing precision requirements while maintaining high delay measurement accuracy.
Solution Approach 2:
The patent performs delay calibration in advance during the initialization phase. The calibration circuit measures the delay values of all transfer paths before normal operation begins, generates calibration codes based on these measurements, and stores them for subsequent use. This preliminary action ensures that timing inconsistencies are compensated before they affect actual data operations, resolving the contradiction between using multiple chips for increased capacity while maintaining operation timing consistency.
Data Source
AI summary
A semiconductor device includes: a first transfer path outputting a first preliminary signal; a second transfer path outputting a second preliminary signal; a third transfer path outputting a third preliminary signal; a first calibration circuit generating a first calibration code corresponding to a difference in delay values between the first transfer path and a selected transfer path having a largest delay value among the first to third transfer paths; a second calibration circuit generating a second calibration code corresponding to a difference in delay values between the second transfer path and the selected transfer path; a third calibration circuit generating a third calibration code corresponding to a difference in delay values between the third transfer path and the selected transfer path; a first delay control circuit generating a first signal; a second delay control circuit generating a second signal; and a third delay control circuit generating a third signal.