Master-Slave Clocked Latch Layout for Low-Delay, Low-Power Storage

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Solution Overview

Problem

Clocked storage elements in digital systems consume significant power and chip area, contributing to increased costs and reduced performance, and existing designs struggle to achieve low insertion delay, small footprint, and low power consumption simultaneously.

Innovation Solution

The design of a compact and fast clocked storage element using a master-slave latch configuration with specific transistor stacks and configurations that eliminate the need for clock signal inversion, reducing insertion delay and power consumption by optimizing transistor paths and layouts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional clocked storage element designs are used, then reliability is maintained, but insertion delay increases and power consumption increases

Engineering Contradiction:
Improveinsertion delayVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The clocked storage element is divided into two separate latches (first latch and second latch) with distinct transistor paths. Each latch handles specific signal transitions, allowing independent optimization of each path for speed and power efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different transistor configurations are used in different parts of the circuit. The first latch uses two p-channel and two n-channel transistors in its current path, while the second latch uses a different arrangement, allowing each section to be optimized for its specific function and reducing overall power consumption while maintaining fast insertion delay.

Inventive Principle:
Principle #3Local quality

2Area of stationary object

If conventional clocked storage element designs are used, then functionality is maintained, but chip area increases

Engineering Contradiction:
Improvechip areaVSAvoidinsertion delay
Core Design Contradiction:
Area of stationary objectVSSpeed

Solution Approach 1:

The master latch and slave latch are merged into a single integrated clocked storage element structure. The latches share common supply lines (VDD and VSS) and are closely coupled, reducing the total chip area while maintaining the fast insertion delay performance through optimized internal transistor paths.

Inventive Principle:
Principle #5Merging (Combining)

3Speed

If clock signal inversion is used in conventional designs, then latch operation is enabled, but insertion delay increases

Engineering Contradiction:
Improveinsertion delayVSAvoidcircuit complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The clock inverter stage is extracted and eliminated from the design. Both latches receive the clock signal directly without inversion, removing the delay associated with clock signal conditioning while simplifying the overall circuit structure and reducing the number of required components.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4391377A1Fast clocked storage element
Publication Date: 2024.06.26 SAMBANOVA SYSTEMS INC
  • EP4391377A1 patent drawingFigure 1~3
  • EP4391377A1 patent drawingFigure 4
  • EP4391377A1 patent drawingFigure 5

AI summary

A clocked storage element comprises a first latch having an input data node, a clock input node and a first latch output data node, and a second latch having an input connected to the first latch output data node, a clock input node and a second latch output data node. The first and second latches can have a clocked pull-up current path consisting of two p-channel transistors between their respective output data nodes and the VDD supply line, and a clocked pull-down current path consisting of two n-channel transistors between their respective output data nodes and the VSS supply line.