Adjustable Delay Line for Memory Command Signal Synchronization
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Solution Overview
Problem
In semiconductor memory, the high frequency of memory clock signals and varying propagation delays due to power, voltage, and temperature conditions complicate the synchronization of internal command and clock signals, leading to improper timing and potential errors in data read and write operations, especially in multi-data rate memories.
Innovation Solution
The implementation of an adjustable delay line and command extension circuit within the control circuit, which includes a clock path and command path, allows for precise synchronization of internal clock and command signals by adjusting delays based on latency values and feedback signals, ensuring correct timing of read and write operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the propagation delay of clock path and command path are modeled to be the same, then the timing synchronization is simplified, but the power consumption increases due to continuous operation of delays and counter circuitry
Solution Approach 1:
The patent implements a dynamic delay adjustment mechanism where the delay amount is not fixed but can be modified based on feedback signals. The delay circuitry operates selectively rather than continuously, adjusting its delay characteristics in response to detected timing conditions, thereby reducing power consumption while maintaining synchronization accuracy.
Solution Approach 2:
The patent employs a feedback mechanism where the actual timing relationship between clock and command signals is monitored, and this information is used to adjust the delay amount dynamically. This closed-loop control allows the system to achieve precise synchronization without requiring continuous operation of all circuitry, thus reducing power consumption.
2Measurement precision
If delays and counter circuitry are run continuously to maintain timing synchronization, then the timing accuracy is improved, but the power consumption becomes higher than desirable
Solution Approach 1:
Instead of continuous operation, the patent implements periodic or event-driven adjustment of delay circuitry. The system monitors timing conditions and activates delay adjustment only when needed, rather than maintaining continuous operation. This periodic action maintains timing accuracy while significantly reducing power consumption during steady-state operation.
Solution Approach 2:
The system incorporates self-adjusting mechanisms where the delay circuitry automatically modifies its own operation based on detected timing conditions. This self-service capability eliminates the need for continuous external control signals, allowing the system to maintain accuracy while consuming less power through intelligent, condition-based operation.
3Loss of time
If the propagation delay of internal paths is relatively long or additional delay circuitry is added, then the timing adjustment range is increased, but the variations due to operating conditions negatively affect the timing
Solution Approach 1:
The patent uses feedback mechanisms to continuously monitor the actual timing relationship and compensate for variations caused by operating conditions such as temperature and voltage changes. This closed-loop control allows the system to maintain accurate timing despite environmental variations, effectively decoupling the timing stability from the propagation delay length.
Solution Approach 2:
The system dynamically adjusts delay parameters based on detected operating conditions and timing requirements. By changing delay characteristics in response to measured conditions, the system can compensate for the negative effects of long propagation delays and environmental variations, maintaining reliable timing across different operating states.
Data Source
AI summary
Apparatuses and methods related to adjusting a delay of a command signal path are disclosed. An example apparatus includes: a command input buffer that receives command signals and further provides buffered command signals; a command decoder coupled to the command input buffer, that decodes the buffered command signals responsive to a first clock signal and further provides a decoded command signal; and a command extension circuit coupled to the command decoder, which receives the decoded command signal, the first clock signal and a second clock signal having a first delay relative to the first clock signal, and further provides a command extension signal having a pulse width longer than the pulse width of the decoded command signal.