Buffer Die Strobe Skew Compensation for Stacked Memory I/O
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Memory devices experience increased power consumption and degraded input/output characteristics due to skew in data strobe signals at high frequencies, which occurs when data is transmitted at high speeds.
Innovation Solution
A buffer die with integrated circuits for generating, dividing, and adjusting strobe signals, along with monitoring and trimming functions, is used to compensate for skew at the wafer level, ensuring only defect-free buffer dies are packaged into stacked memory devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If data is transmitted at high speed, then bandwidth is improved, but power consumption increases and skew occurs in data strobe signals
Solution Approach 1:
The patent applies preliminary action by performing skew compensation through duty cycle adjustment before data transmission occurs. The buffer die adjusts the duty cycle of data strobe signals in advance to compensate for anticipated skew, ensuring signal integrity without requiring additional power-intensive corrections during high-speed operation. This pre-adjustment mechanism allows the system to maintain high transmission speeds while avoiding the power consumption penalty of real-time skew correction.
2Speed
If data strobe signal frequency is increased, then bandwidth is improved, but skew occurs and input/output characteristics are degraded
Solution Approach 1:
The patent implements parameter changes by dynamically adjusting the duty cycle parameter of data strobe signals to compensate for skew. The buffer die monitors signal characteristics and modifies the duty cycle parameter in response to detected skew conditions, thereby maintaining signal integrity and input/output characteristics even at high frequencies. This parameter adjustment mechanism enables the system to operate reliably at elevated data strobe signal frequencies without degrading performance.
3Manufacturing precision
If wafer level testing and trimming is performed, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent applies merging by integrating the skew compensation functionality directly into the buffer die structure. The duty cycle adjustment circuit, skew monitoring circuit, and trimming circuit are combined within the buffer die itself, eliminating the need for separate external compensation components. This integration achieves high manufacturing precision for skew compensation while minimizing the increase in device complexity through functional consolidation rather than additive componentry.
Data Source
AI summary
A buffer die provided in a wafer includes a write strobe signal generation circuit configured to, based on being enabled in a wafer level test on the buffer die, generate a first write strobe signal and a second write strobe signal having a phase difference of 180 degrees, a dividing and converting circuit configured to generate a plurality of divided clock signals having a phase difference of 90 degrees, a duty cycle adjusting circuit configured to generate a plurality of adjusted clock signals, a read strobe signal generation circuit configured to generate a first read strobe signal and a second read strobe signal having a phase difference of 180 degrees, a skew monitoring circuit configured to generate a first up/down signal, a trimming circuit is configured to generate a second up/down signal, generate a plurality of control code sets, and obtain a fuse calibration code.