Delayed Timing Signal Calibration for Processor-Memory Data Links
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Solution Overview
Problem
In computing systems, the synchronization of timing signals between processor and memory integrated circuits during read and write operations is challenging due to variations in delay, which can lead to data transmission errors and inefficiencies.
Innovation Solution
The implementation of a system that includes delay circuits and buffer circuits to calibrate and synchronize timing signals, using test patterns and phase comparison signals to adjust delays, ensuring that the timing signals are aligned during both normal and calibration modes, thereby maintaining data integrity and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If timing signals are transmitted between processor and memory integrated circuits, then data transmission is enabled, but delay variations cause synchronization errors and data transmission errors
Solution Approach 1:
The patent applies preliminary action by performing delay calibration before normal data transmission operations. A calibration mode is implemented where test patterns are transmitted and delay measurements are taken to determine optimal delay values. These pre-determined delay values are then programmed into delay circuits for use during normal operations, ensuring synchronization without requiring real-time adjustment during data transmission.
Solution Approach 2:
The patent implements feedback mechanisms where phase comparison signals are generated by comparing transmitted test patterns with received signals. This feedback information is used to measure actual delay values and adjust delay circuit parameters accordingly. The system continuously monitors timing relationships and provides feedback to optimize synchronization, resolving the contradiction between maintaining accurate timing and accommodating delay variations.
2Measurement precision
If delay calibration is performed using test patterns and phase comparison, then timing synchronization accuracy is improved, but system complexity and power consumption increase
Solution Approach 1:
The patent applies universality by designing calibration circuits that can serve multiple functions. The same delay circuits used for timing adjustment during calibration mode are also used during normal data transmission mode. Phase comparison circuits and delay measurement mechanisms are integrated into the existing data path infrastructure, allowing a single set of components to perform both calibration and operational functions, thereby reducing overall system complexity.
Solution Approach 2:
The system implements self-service through automated delay calibration processes. The calibration mode automatically generates test patterns, transmits them through the data path, measures delays using phase comparison, and programs the optimal delay values back into the delay circuits without requiring external intervention. This self-calibrating capability reduces the need for complex external testing equipment and manual adjustment mechanisms.
3Adaptability or versatility
If multiple delay values are programmed based on delay ranges, then adaptability to different conditions is improved, but programming complexity and time increase
Solution Approach 1:
The patent applies partial action by implementing a tiered delay calibration approach. Instead of calibrating every possible delay scenario, the system divides the delay range into multiple segments or ranges and programs representative delay values for each range. This partial calibration approach provides sufficient adaptability for varying conditions while significantly reducing the total number of calibration steps and programming time required compared to exhaustive calibration of all possible delay values.
Data Source
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AI summary
An integrated circuit includes a delay circuit and first and second interface circuits. The delay circuit delays a first timing signal by an internal delay to generate an internal timing signal. The first interface circuit communicates data to an external device in response to the internal timing signal. The second interface circuit transmits an external timing signal for capturing the data in the external device. An external delay is added to the external timing signal in the external device to generate a delayed external timing signal. The delay circuit sets the internal delay based on a comparison between the delayed external timing signal and a calibration signal transmitted by the first interface circuit.