SoC Memory Calibration Reuse for Faster Boot Time
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Solution Overview
Problem
The calibration of external memory components in system-on-chip (SoC) devices is time-consuming, particularly for high-frequency and low-power memory types like LPDDR4, which can exceed boot time performance requirements for devices such as mobile phones and tablets.
Innovation Solution
A method where a secondary SoC receives previous calibration parameters from a primary SoC, determines their validity, and operates the external component based on these parameters, with the option to recalibrate if they are invalid, thereby reducing boot time by leveraging stored calibration data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external memory components are calibrated during boot sequence, then the memory operates at correct timing parameters, but the boot time exceeds performance requirements
Solution Approach 1:
The patent performs memory calibration before device assembly by injecting calibration patterns through test access ports (TAPs) during manufacturing. The determined calibration parameters are stored in non-volatile memory, eliminating the need for time-consuming calibration during the boot sequence. This preliminary action resolves the contradiction by ensuring memory operates correctly without adding boot time.
Solution Approach 2:
The patent replaces the traditional runtime calibration mechanism with a manufacturing-time calibration approach using JTAG TAP interfaces. Instead of calibrating through software during boot, the system uses hardware-based pattern injection and measurement during manufacturing, substituting the calibration process from a software/runtime operation to a hardware/manufacturing operation.
2Measurement precision
If calibration parameters are determined during boot sequence, then the parameters are valid for the specific device, but the calibration process takes significant time
Solution Approach 1:
The patent performs calibration parameter determination during the manufacturing process rather than during device operation. By completing the time-consuming measurement and optimization process beforehand, the system ensures accurate, device-specific parameters are available immediately at boot without sacrificing precision.
Solution Approach 2:
The calibration process uses the device's own hardware resources (TAP interfaces, test logic, measurement circuits) to perform self-calibration during manufacturing. The device calibrates itself without requiring external calibration equipment or post-manufacturing intervention, making the process efficient and device-specific.
3Productivity
If full calibration is performed every boot, then the memory timing is optimized, but the boot sequence is delayed
Solution Approach 1:
The patent extracts the calibration process from the runtime boot sequence and relocates it to the manufacturing process. By removing calibration from the operational timeline, the system achieves both fast boot speeds and optimized memory timing, as calibration no longer competes with boot operations for time resources.
Solution Approach 2:
The system performs memory timing optimization in advance during manufacturing, storing the results for immediate use during operation. This preliminary optimization ensures memory timing is always optimized without requiring repeated calibration during boot, thus maintaining both productivity and reliability.
Data Source
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AI summary
Various additional and alternative aspects are described herein. In some aspects, the present disclosure provides a method of calibrating a component. The method includes receiving previous calibration parameters for an external component at a secondary SoC from a primary SoC, wherein the secondary SoC is coupled to the extemal component and configured to calibrate the external component. The method further includes determining validity of the previous calibration parameters by the secondary SoC. The method further includes operating the external component by the secondary SoC based on the determined validity of the previous calibration parameters.