Multiphase One-Shot Control Circuit for Large Shift Registers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shift register control systems are unreliable when controlling a large number of stages due to the dependency of control signal effectiveness on data in the stages, leading to inefficiencies in generating multiphase control signals.
Innovation Solution
A circuit using a chain of one-shot circuits to generate multiphase control signals for shift register chains, where each one-shot circuit comprises a bi-stable circuit with reset inputs to ensure pulse termination only after a sufficient logic level change, and data sampling circuits are used to maintain up-front data sampling speed without delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a chain of inverters is used to generate control signals for a large number of shift register stages, then the control signals can be generated with simple circuitry, but the reliability of control decreases when controlling large numbers of stages
Solution Approach 1:
The control signal generation is segmented into multiple one-shot circuits, each responsible for generating control signals for a specific group of shift register stages. This segmentation isolates the control signal generation for each stage group, preventing the cumulative loading effects that plague inverter chains when controlling large numbers of stages, thus maintaining reliability while keeping individual circuit segments simple.
Solution Approach 2:
One-shot circuits serve as intermediary elements between the clock signal source and the shift register stages. These intermediaries actively regenerate and reshape the control signals, ensuring clean, reliable pulse transitions even when driving large numbers of stages, thereby decoupling the simplicity of the source clock from the reliability requirements of the distributed stage control.
2Ease of manufacture
If control signals are generated using inverter chains, then the circuit implementation is simple, but the control effectiveness depends on the data in the stages
Solution Approach 1:
Each one-shot circuit is self-regulating through its internal bi-stable circuit and feedback mechanism. The circuit automatically detects when a sufficient logic level change has occurred and terminates its pulse accordingly, making the control signal generation independent of the data state in the shift register stages while maintaining simple implementation.
Solution Approach 2:
The one-shot circuits incorporate feedback paths that monitor the output signal levels and automatically terminate pulses when the desired logic level change is achieved. This feedback mechanism ensures reliable control signal generation that is independent of downstream data states, while the overall circuit structure remains simple and manufacturable.
3Speed
If pulses are terminated early to speed up control, then the response time decreases, but the logic level change may be insufficient to control functional circuits
Solution Approach 1:
The manual or data-dependent pulse termination mechanism is replaced with an automated voltage-level detection system using bi-stable circuits. This electronic substitution automatically senses when the output has reached the required logic level and terminates the pulse at the optimal moment, ensuring both speed and sufficient logic level change without manual intervention or data dependency.
4Loss of time
If up-front data sampling is performed, then data is captured early, but delays in control signal generation may affect sampling speed
Solution Approach 1:
Data sampling is performed in advance during a dedicated sampling phase before the shift register stages begin their normal operation. The one-shot control circuits are designed to generate their control pulses after the sampling is complete, ensuring that the preliminary data capture action is not interfered with by subsequent control signal delays, thus preserving both early sampling and fast response.
Data Source
AI summary
A circuit has a plurality of functional circuits (100a-f), each with multiphase control inputs. A control circuit drives the inputs for each phase in parallel. The control circuit (120a-c) comprises a chain of one-shot circuits (120a-c), each comprising a bi-stable circuit (121). The bi-stable circuit (121) of a first one-shot circuit in the chain has a set input coupled to the basic control signal input (126), the bi-stable circuits (121) of a remaining or each remaining one-shot circuit (120a-c) in the chain have a set input output of its predecessor in the chain. Each bi-stable circuit (121) has an output coupled to a respective one of the multiphase control outputs (14a-c) and a reset input coupled to the respective one of the multiphase control outputs (14a-c). Loading of the multiphase control outputs (14a-c) by the functional circuits results in a delay of the reset. Thus the pulse durations of the one shot circuits are adapted to the number of functional circuits to ensure sufficient signal development.