On-Die Termination Circuit Reset Logic for High-Impedance Matching
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Solution Overview
Problem
Existing on-die termination circuits for semiconductor memory apparatuses face code adjustment errors due to external impedance, leading to infinite resistance values and inaccurate data input/output operations.
Innovation Solution
An on-die termination circuit and method that includes a driving unit dividing an input voltage based on a resistance ratio determined by a code with at least two bits, and an on-die termination control unit that compares the line voltage with a reference voltage, counting or resetting the code to prevent code adjustment errors by ensuring the resistance ratios of the driving unit and external resistor match the reference voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the first code Pcode is continuously increased and the second code Ncode is continuously decreased to match high external impedance, then the resistance values approach infinite values, but code adjustment errors occur and accurate data input/output cannot be performed
Solution Approach 1:
The patent applies preliminary anti-action by detecting when the code is approaching extreme values (maximum or minimum) before actual code adjustment errors occur. The detection unit monitors the code values and generates reset signals in advance to prevent the resistance from approaching infinite values, thereby preventing data input/output failures before they happen.
Solution Approach 2:
The patent implements feedback through a detection unit that continuously monitors the code values (Pcode and Ncode) and compares them against predefined threshold values. When the monitored code approaches extreme values, the detection unit generates a reset signal that feeds back to the control unit, which then resets the code to appropriate values, ensuring continuous accurate impedance matching.
2Reliability
If the resistance values are increased to match high external impedance, then the line voltage can be matched to reference voltage, but the code values reach maximum/minimum limits causing termination failure
Solution Approach 1:
The patent applies dynamics by making the code values adjustable and resettable based on real-time detection. Instead of fixed extreme values, the system dynamically monitors code values and resets them when approaching thresholds, allowing the impedance matching to adapt continuously without reaching failure states.
Solution Approach 2:
The patent changes the parameter monitoring approach by introducing threshold-based detection for code values. When the code Pcode or Ncode approaches maximum or minimum values respectively, the system detects this parameter change and triggers a reset, thereby maintaining the resistance within effective ranges for accurate impedance matching.
3Measurement precision
If the ODT controller continuously counts the code to achieve impedance matching, then the line voltage can be adjusted, but code adjustment errors occur due to external impedance causing infinite resistance values
Solution Approach 1:
The patent applies preliminary action by implementing a detection unit that monitors code values before they reach extreme states. The detection unit identifies when codes are approaching maximum or minimum values and triggers reset signals in advance, preventing the system from entering a failed state where resistance becomes infinite and termination operations fail.
Solution Approach 2:
The patent implements feedback by creating a closed-loop system where the detection unit continuously monitors code values and feeds this information back to the control unit. When threshold values are approached, the feedback triggers automatic code resetting, ensuring continuous reliable impedance matching without code adjustment errors.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents code adjustment errors, allowing for accurate data input/output operations even with high external impedance, thereby improving the reliability of memory operations.
Implementation Method 1
a driving unit that receives a code having at least two bits, divides an input voltage on the basis of a resistance ratio according to the code, and outputs the divided voltage
Implementation Method 2
an on-die termination control unit that counts the code or resets the code to an initial value according to whether or not a line voltage according to the resistance ratio of the driving unit and a resistance ratio of an external resistor unit are consistent with a reference voltage
Data Source
AI summary
An on-die termination circuit for semiconductor memory apparatus includes an ODT (On Die Termination) input driving unit that divides an input voltage on the basis of a resistance ratio according to a first code Pcode<0:N> having at least two bits and outputs a first line voltage, a first ODT control unit that counts the first code or resets the first code to a first set value according to whether or not the first line voltage and a reference voltage match with each other, an ODT output driving unit that divides an input voltage on the basis of the resistance ratio according to the first code and a resistance ratio according to a second code having at least two bits and outputs a second line voltage, and a second ODT control unit that counts the second code or resets the second code to a second set value according to whether or not the second line voltage and the reference voltage are consistent with each other.