Clock Phase Control for Uniform Semiconductor Write Training
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Solution Overview
Problem
The existing write training operation in semiconductor devices is inefficient due to varying initial phase relationships between the signal and system clock, leading to increased time in recognizing logic values and synchronizing edges, especially when transmission channels have different lengths.
Innovation Solution
A semiconductor device with a sampling unit, edge detection unit, and phase control unit that periodically changes the clock delay code to adjust the phase of the operation clock, allowing for precise synchronization and edge detection, even with varying initial conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a specific initial period is allocated for write training operation to adjust phase relationship, then synchronization accuracy is improved, but operation time is increased
Solution Approach 1:
The patent applies preliminary action by performing write training operation during an initial period before normal operations begin. The phase relationship between system clock and signal is adjusted in advance during this initial period, ensuring that synchronization is established before data transmission starts. This allows the system to achieve accurate synchronization (improving measurement precision) while confining the time penalty to only the initial setup phase rather than continuous operation.
2Measurement precision
If channel length differences are compensated for to achieve precise edge placement, then synchronization accuracy is improved, but device complexity is increased
Solution Approach 1:
The patent applies parameter changes by adjusting the phase of the system clock as a controllable parameter to compensate for channel length differences. Instead of adding complex physical compensation mechanisms, the system varies the phase parameter of the clock signal to align the specific edge with the center of the data signal. This approach achieves precise edge placement accuracy while avoiding increased device complexity by using software/firmware-based phase adjustment rather than hardware modifications.
3Reliability
If source synchronization method is used to transmit signal and system clock, then setup and hold time requirements are met, but phase adjustment complexity is increased
Solution Approach 1:
The patent applies feedback by implementing a write training operation that monitors the phase relationship between the system clock and data signal, then adjusts the clock phase accordingly. During the initial period, the system observes whether the specific edge of the system clock is properly positioned at the center of the data signal and modifies the clock phase to achieve optimal alignment. This feedback mechanism ensures reliable signal recognition (meeting setup and hold time requirements) while using a systematic phase adjustment process rather than complex ad-hoc adjustments.
Data Source
AI summary
A semiconductor device includes a sampling unit suitable for sampling a logic value of an input signal based on an edge of an operation clock to output a sampling signal, an edge detection unit suitable for detecting an edge of the input signal based on the sampling signal, and a phase control unit suitable for controlling a phase of the operation clock while periodically changing a value of a clock delay code at each predetermined period and substituting a code value, which is obtained by calculating a value of the clock delay code corresponding to a time point at which an operation of the edge detection unit is completed and a value of a pre-phase code determined based on the sampling signal, for the clock delay code.