Dynamic ODT Control for I/O Interface Noise and Impedance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing swing width of data signals between a system on chip (SoC) and a memory device leads to increased external noise and impedance mismatching in input/output interfaces, which existing technologies struggle to address effectively.
Innovation Solution
A method of operating an input/output interface that selects and uses appropriate output driver circuits and input receiver circuits based on a mode selection signal, which is generated according to memory latency and a mode register set command, to adjust operation frequency and termination levels, thereby optimizing data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the swing width of data signal is increased to improve transmission speed, then data transmission speed is improved, but external noise influence and impedance mismatching increase
Solution Approach 1:
The patent changes the termination resistance value parameter dynamically based on the data signal swing width. When swing width increases, the termination resistance is adjusted to match the new impedance characteristics, thereby maintaining signal integrity and reducing noise influence while preserving the high-speed transmission benefit
Solution Approach 2:
The patent implements dynamic adjustment of the ODT circuit's termination resistance rather than using a fixed resistance value. The termination resistance is modified in response to changing swing width conditions, allowing the system to adapt to different transmission scenarios and maintain optimal performance across varying speed requirements
2Speed
If the swing width of data signal is increased to improve transmission speed, then data transmission speed is improved, but impedance mismatching in input/output interface increases
Solution Approach 1:
The patent dynamically changes the termination resistance parameter to match the impedance characteristics corresponding to different swing width values. This ensures that even when swing width increases for higher speed, the impedance matching is maintained by adjusting the termination resistance accordingly
Solution Approach 2:
The system uses feedback about the actual swing width to adjust the termination resistance value. The ODT circuit monitors transmission conditions and modifies its termination resistance to maintain proper impedance matching, creating a closed-loop system that preserves reliability while enabling speed improvements
3Device complexity
If a fixed termination resistance is used in ODT circuit, then device complexity is reduced, but adaptability to different operation modes is limited
Solution Approach 1:
The patent transforms the static ODT circuit into a dynamic one by adding control logic that adjusts the termination resistance based on swing width conditions. This dynamic capability enables the circuit to adapt to different operation modes and swing width values without requiring multiple separate circuits
Solution Approach 2:
The ODT circuit is designed to perform multiple functions by dynamically adjusting its termination resistance. A single ODT circuit structure serves different swing width conditions and operation modes, replacing what would otherwise require multiple fixed-resistance circuits, thus maintaining simplicity while achieving versatility
Data Source
AI summary
A method of operating an input/output interface includes selecting one of a plurality of output driver circuits according to a mode selection signal, and outputting a data signal using the selected one of the plurality of output driver circuits. Another method of operating an includes generating a mode selection signal based on a received command signal, and controlling an on-die termination (ODT) circuit included in the input/output interface according to the mode selection signal. Another method of operating an includes generating a mode selection signal based on a received command signal, and controlling an ODT circuit included in the input/output interface according to the mode selection signal.