DRAM Phase Calibration via Test Data Verification
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Solution Overview
Problem
Existing methods for adjusting memory signal phases in DRAM systems are inadequate in addressing phase skew caused by varying hardware components and ambient conditions, leading to operational errors and inconvenience in manufacturing and user experience.
Innovation Solution
A method that involves writing test data into DRAM, generating a data strobe signal, offsetting its phase to verify the data, and calculating a target offset value to adjust the signal phase for accurate data access, thereby reducing phase skew and ensuring proper operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a DLL is used to synchronize the memory clock signal phase with the reference clock signal, then the phase synchronization is improved, but signal skew still occurs due to ambient variations and hardware component uncertainties
Solution Approach 1:
The patent applies preliminary action by performing phase calibration before normal memory operations. The memory controller writes test data to the DRAM, reads it back, and determines an optimal phase offset value before actual data access operations begin. This preliminary calibration ensures that subsequent operations start with optimized phase alignment, preventing signal skew issues that would otherwise occur during normal operation.
Solution Approach 2:
The patent implements feedback by using the read-back test data to determine the optimal phase offset. The memory controller compares the written test data with the read-back data, analyzes the phase relationship, and adjusts the memory clock signal phase based on this feedback information. This closed-loop feedback mechanism continuously optimizes the phase alignment to compensate for ambient variations and hardware uncertainties.
2Manufacturing precision
If the phase of the data strobe signal is adjusted manually in the factory according to hardware characteristics, then the initial operation is improved, but the apparatus cannot operate normally under different operating conditions after a long time
Solution Approach 1:
The patent performs preliminary phase calibration automatically during system initialization or at predetermined intervals, eliminating the need for manual factory adjustment. The memory controller automatically writes test data, reads it back, determines the optimal phase offset, and configures the memory clock signal phase before normal operations begin. This preliminary automated calibration replaces manual adjustment and enables the system to adapt to different hardware characteristics and operating conditions.
Solution Approach 2:
The patent implements self-service by enabling the memory controller to automatically calibrate its own phase without external intervention. The system writes test data to its own memory, reads it back, analyzes the phase relationship, and adjusts its own clock signal phase based on the analysis. This self-calibration capability allows the system to maintain optimal performance under varying operating conditions without requiring manual re-adjustment or external calibration equipment.
3Reliability
If one by one adjustment of apparatuses with operational problems is performed, then the operational issues are resolved, but great inconvenience is caused to manufacturers and users
Solution Approach 1:
The patent applies universality by implementing a universal phase calibration procedure that works for all memory devices in the system. The same calibration routine can be executed on any DRAM module, automatically determining the optimal phase offset for each device based on its specific characteristics. This universal approach eliminates the need for device-by-device manual adjustment, making the calibration process convenient for both manufacturers and users while ensuring reliable operation for all apparatuses.
Data Source
AI summary
A method for adjusting a memory signal phase is applied to data access between a memory controller and a dynamic random access memory (DRAM) of an electronic apparatus. The method includes writing a test data into the DRAM by the memory controller in response to a predetermined status of the electronic apparatus; generating a first data strobe signal; offsetting a phase of the first data strobe signal to access and verify the test data to generate a verification result; generating a target offset value in response to the verification result; and offsetting the phase of the first data strobe signal by the target offset value for subsequent operations.