Command Path Delay Calibration for Memory Timing Accuracy
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Solution Overview
Problem
High-speed semiconductor memory systems face challenges in accurately timing internal clock and command signals due to high frequency memory clock signals and varying propagation delays, leading to potential errors in data retrieval and operation.
Innovation Solution
The implementation of a distributed clock and command path system that uses a delay-lock loop and timing calibration block to synchronize clock and command signals, reducing power consumption by eliminating continuous counter operation and adjusting delays dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If delays and counter circuitry run continuously to model clock and command paths, then timing accuracy is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic calibration of delay circuits instead of continuous operation. The delay circuits are calibrated at specific intervals or under specific conditions (e.g., during initialization or when operating conditions change), allowing the system to maintain timing accuracy while reducing power consumption by keeping calibration circuitry inactive during normal operation.
Solution Approach 2:
The patent uses dynamically adjustable delay circuits that can adapt their delay values based on operating conditions. The delay circuits are calibrated to match actual clock and command path delays under different power, voltage, and temperature conditions, allowing the system to maintain timing accuracy across varying operational states without continuous calibration.
2Measurement precision
If propagation delay variations due to power, voltage, and temperature conditions are accounted for, then timing accuracy is improved, but device complexity increases
Solution Approach 1:
The patent implements feedback mechanisms where the calibrated delay values are used to adjust the operation of command and clock paths. The system continuously monitors timing relationships and adjusts delay circuit values to maintain synchronization, creating a closed-loop control system that compensates for variations in power, voltage, and temperature conditions.
Solution Approach 2:
The patent changes the delay parameters of internal circuits based on calibrated measurements. By adjusting the delay values in delay circuits to match actual propagation delays under different operating conditions, the system compensates for parameter variations without requiring complex additional circuitry.
3Device complexity
If clock and command paths are modeled with the same propagation delay, then device complexity is reduced, but timing accuracy deteriorates
Solution Approach 1:
The patent segments the clock path and command path into separate delay circuits, each with independently calibrated delay values. This allows the system to account for the different propagation delays of each path while maintaining a relatively simple overall structure. Each segment can be calibrated and adjusted independently to match its actual propagation characteristics.
Solution Approach 2:
The patent introduces delay circuits as intermediary elements between the clock source and the command execution unit. These intermediary delay circuits act as adjustable buffers that can be calibrated to match the actual propagation delays of their respective paths, providing timing alignment without requiring complex redesign of the fundamental clock and command paths.
Data Source
AI summary
Command paths, apparatuses, and methods for providing a command to a data block are described. In an example command path, a command receiver is configured to receive a command and a command buffer is coupled to the command receiver and configured to receive the command and provide a buffered command. A command block is coupled to the command buffer to receive the buffered command. The command block is configured to provide the buffered command responsive to a clock signal and is further configured to add a delay before to the buffered command, the delay based at least in part on a shift count. A command tree is coupled to the command block to receive the buffered command and configured to distribute the buffered command to a data block.