Dynamic Duty Cycle Correction for DDR Clock Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The Toggle Mode Double Data Rate (DDR) interface in storage systems faces duty cycle distortion issues due to various components in the clock signal path, leading to reduced signal integrity and data transfer performance, which existing technologies fail to effectively address.
Innovation Solution
A dynamic duty cycle correction method is implemented in the controller of a storage system, where a clock signal with a target duty cycle is provided to the memory, monitored for distortions, and adjusted using a duty cycle control circuit and monitor to maintain optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If simulations are run during design phase to determine parasitics and select IO driver strengths, then duty cycle distortion can be budgeted and managed, but the system cannot dynamically adapt to actual duty cycle deviations that occur during operation
Solution Approach 1:
The patent implements preliminary action by measuring the duty cycle of the clock signal during the design phase and storing the measured value in a lookup table. This pre-characterization allows the system to quickly compensate for duty cycle distortion during operation by selecting pre-calculated compensation values based on the actual measured duty cycle, rather than requiring real-time complex calculations.
Solution Approach 2:
The patent employs feedback by continuously monitoring the duty cycle of the clock signal using a duty cycle measurement circuit. The measured duty cycle value is fed back to control logic that adjusts the clock signal generation parameters (such as phase or frequency) to maintain the desired duty cycle, creating a closed-loop control system that adapts to changing conditions.
2Reliability
If the controller provides a clock signal with duty cycle at or near 50%, then signal integrity and data transfer performance are optimized, but various distortions in the clock signal path alter the duty cycle
Solution Approach 1:
The patent applies preliminary anti-action by pre-characterizing the duty cycle distortion of the clock signal path during the design phase and storing compensation values in a lookup table. Before normal operation, the system measures the actual duty cycle and selects the appropriate compensation value, thereby counteracting the expected distortion before it affects data transfer performance.
Solution Approach 2:
The patent uses feedback by implementing a duty cycle measurement circuit that continuously monitors the clock signal duty cycle. The measured value is fed back to control logic that adjusts clock generation parameters in real-time to compensate for distortions introduced by the clock signal path, maintaining the desired 50% duty cycle for optimal signal integrity.
3Ease of manufacture
If duty cycle distortion is addressed through design phase simulations and fixed IO driver selection, then initial performance can be optimized, but the system lacks the capability to correct distortions that vary with operating conditions
Solution Approach 1:
The patent implements preliminary action by pre-characterizing the duty cycle properties of the clock signal path during the design phase and storing these measurements in a lookup table. This approach simplifies the design process by replacing complex real-time calculations with pre-computed values, while still enabling dynamic compensation during operation to maintain high data transfer performance.
Solution Approach 2:
The patent employs feedback by measuring the actual duty cycle of the clock signal and using this information to adjust operating parameters in real-time. This closed-loop approach allows the system to adapt to varying operating conditions (such as temperature changes or process variations) that affect duty cycle, thereby maintaining optimal productivity without requiring complex real-time simulations.
Data Source
AI summary
A storage system and method for dynamic duty cycle correction are disclosed. In one embodiment, a controller of a storage system provides a clock signal to the memory, receives the clock signal back from the memory, monitors the duty cycle of the clock signal received back from the memory, and in response to the duty cycle of the clock signal received back from the memory not meeting a target value, adjusts the duty cycle of the clock signal provided to the memory so that the duty cycle of the clock signal received back from the memory better meets the target value. Other embodiments are possible, and each of the embodiments can be used alone or together in combination.