Deskew Timing Cells for Signal Edge and Pulse Width Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing test systems face challenges in synchronizing timing signals to device under test (DUT) due to differences in signal propagation paths, leading to timing errors such as skew, which affect test results.
Innovation Solution
A deskew system using multiple timing control cells coupled in series, where each cell can delay and adjust pulse width based on control codes, allowing for precise synchronization of test signals by combining early and late signal inputs through summing circuits and pulse width adjustment circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple manually adjustable potentiometers are used for each pin to align input signals, then timing synchronization can be achieved, but device complexity and ease of operation deteriorate due to manual adjustment requirements
Solution Approach 1:
The patent replaces manual mechanical potentiometer adjustment with an automated digital control system. A controller generates control signals that automatically adjust delay amounts for each pin based on stored calibration data, eliminating the need for manual mechanical adjustment while maintaining timing synchronization precision.
Solution Approach 2:
The system performs self-calibration by automatically applying calibration signals, measuring response times, and storing the results in a lookup table. This self-service approach eliminates the need for external manual intervention during calibration, reducing both device complexity and operational burden while maintaining precise timing alignment.
2Measurement precision
If multiple manually adjustable potentiometers are used for each pin to align input signals, then timing synchronization can be achieved, but ease of operation worsens due to manual adjustment requirements
Solution Approach 1:
The patent replaces manual mechanical potentiometer adjustment with an automated digital control system. A controller generates control signals that automatically adjust delay amounts for each pin based on stored calibration data, eliminating the need for manual mechanical adjustment while maintaining timing synchronization precision.
Solution Approach 2:
The system performs self-calibration by automatically applying calibration signals, measuring response times, and storing the results in a lookup table. This self-service approach eliminates the need for external manual intervention during calibration, reducing both device complexity and operational burden while maintaining precise timing alignment.
3Measurement precision
If coarse and fine delay stages are used for signal deskewing, then timing accuracy can be improved, but device complexity increases due to multiple delay stages
Solution Approach 1:
The patent segments the delay adjustment into two distinct stages: a coarse delay stage that provides large-step adjustments using a delay latch, and a fine delay stage that provides precise incremental adjustments using a delay line with selectable taps. This segmentation allows each stage to be optimized independently, achieving high overall precision without requiring a single overly complex delay mechanism.
Solution Approach 2:
The system dynamically switches between coarse and fine adjustment modes based on the required precision level. The coarse stage quickly brings the timing alignment close to the target, while the fine stage provides precise final adjustment. This dynamic two-stage approach reduces overall device complexity compared to using only a high-precision single-stage system.
Data Source
AI summary
A deskew system can be used to adjust signal characteristics such as pulse width and edge timing. In an example, a deskew system can include multiple timing control cells and each cell can operate in one of multiple different modes according to respective mode control signals. The modes can include at least a signal delay mode and a signal pulse width adjustment mode. In an example, a first cell in a deskew system can be configured to receive a test input signal at a first input node and, in response, provide a deskew output signal at a first output node. The deskew output signal can be based on the test input signal, a pulse width adjustment provided by the first cell, and on a delayed signal, corresponding to the input signal, that is provided by a subsequent cell in the series.