RQL Circuit Synthesis Using Flip-Flop Placeholders and Clock Phases
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current CMOS synthesizers struggle to efficiently design Reciprocal Quantum Logic (RQL) circuits, particularly due to the inability to replicate edge-triggered flip-flop devices, which are essential for synchronous design methodologies, as they require sequential and combinatorial behavior not supported by typical RQL synthesis tools.
Innovation Solution
A method involving a synthesis tool that generates RQL netlist circuits with flip-flop device placeholders, which are then replaced with sequentially controlled flip-flop devices and separated into subsystems based on clock phases, allowing for the simulation and optimization of RQL circuits by emulating CMOS designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CMOS synthesis tools are used for RQL circuit design, then design efficiency is improved, but the inability to replicate edge-triggered flip-flop devices causes functional limitations
Solution Approach 1:
The patent creates a placeholder flip-flop device that copies the essential functionality of a CMOS edge-triggered flip-flop in the RQL domain. This placeholder is then systematically replaced with equivalent RQL circuitry through the synthesis process, allowing the design tool to work with familiar CMOS abstractions while generating functional RQL circuits.
Solution Approach 2:
The placeholder flip-flop device serves as an intermediary element during synthesis. It allows the CMOS synthesis tool to proceed with standard synthesis operations while the placeholder marks locations that will later be converted to actual RQL flip-flop implementations, bridging the gap between CMOS design methodology and RQL implementation.
2Adaptability or versatility
If sequential flip-flop devices are introduced into RQL netlist circuits, then clock-triggered functionality is achieved, but circuit complexity increases
Solution Approach 1:
The synthesis process segments the circuit into phases based on clock cycles, allowing sequential operations to be distributed across different time phases. This segmentation enables the circuit to achieve flip-flop functionality without requiring complex simultaneous switching, as each phase handles specific operations independently.
Solution Approach 2:
The patent utilizes periodic clock phases to control the timing and sequencing of operations in the RQL circuit. By distributing operations across multiple clock phases, the circuit achieves sequential behavior similar to flip-flops while maintaining a regular, periodic structure that is easier to implement and analyze than arbitrary complex timing.
3Reliability
If circuit systems are separated into multiple subsystems based on clock phases, then proper phase sequencing is achieved, but design and verification difficulty increases
Solution Approach 1:
The synthesis tool is enhanced to perform multiple functions: it generates the phased subsystem structure, manages the placeholder flip-flop replacements, and verifies the resulting circuit behavior. This universal tool eliminates the need for separate verification processes, reducing overall verification complexity despite the increased structural complexity of the circuit.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A method for generating a Reciprocal Quantum Logic (RQL) circuit design via a synthesis tool. The method includes providing data associated with behavior and constraints of the RQL circuit design and a component library to the synthesis tool. The method also includes generating an RQL netlist circuit comprising a flip-flop device placeholder and a circuit system coupled to at least one of an input and an output of the flip-flop device placeholder via the synthesis tool based on the data and a component library. The method also includes separating the circuit system into circuit subsystems that are each associated with a separate respective phase of a clock signal via the synthesis tool based on inputs. The method further includes removing the flip-flop device placeholder from the RQL netlist circuit via the synthesis tool to generate the RQL circuit design from the RQL netlist circuit.