Clock Enable Latch Circuit for Race-Free Low-Voltage Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor integrated circuits (ICs) become smaller and more complex, they face challenges with decreasing operating voltages, leading to susceptibility to process, voltage, and temperature (PVT) variations, race conditions, and limited immunity to clock slew variations, which affect their performance.
Innovation Solution
The implementation of a clock circuit with a single clock enable path controlled by a clock trigger circuit, which adjusts the output clock signal based on latch output signals and a reset signal, providing better immunity to PVT variations and allowing a larger range of operating voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If traditional clock circuits are used with decreasing operating voltages, then device complexity is reduced, but reliability deteriorates due to susceptibility to PVT variations and race conditions
Solution Approach 1:
The clock circuit is segmented into distinct functional blocks: a latch circuit that latches the enable signal, a memory state latch circuit that latches the output clock signal, a memory state trigger circuit that generates the output clock signal, and a clock trigger circuit that controls the timing. This segmentation allows each block to be optimized for its specific function while maintaining overall reliability under PVT variations.
Solution Approach 2:
The circuit employs feedback mechanisms where the latch output signal feeds into the memory state trigger circuit, and the output clock signal is fed back to the memory state latch circuit. This feedback ensures proper timing relationships and prevents race conditions by ensuring that signals are properly synchronized and stable before being used to trigger subsequent events.
2Use of energy by moving object
If traditional clock circuits operate at lower voltages, then power consumption is reduced, but reliability worsens due to race conditions and limited immunity to clock slew variations
Solution Approach 1:
The latch circuit performs preliminary action by latching the enable signal before it is used to trigger the clock generation. This ensures that the enable signal is stable and established before it controls the subsequent clock signal generation, preventing race conditions where the clock might trigger before the enable signal is properly established.
Solution Approach 2:
The circuit provides beforehand cushioning by using the memory state latch circuit to hold the output clock signal until it is properly regenerated by the memory state trigger circuit. This cushioning effect ensures that even if there are voltage fluctuations or slew rate variations, the clock signal remains stable and properly timed, preventing race conditions.
3Reliability
If a single clock enable path is implemented, then reliability improves through better immunity to PVT variations, but device complexity increases
Solution Approach 1:
The clock trigger circuit serves multiple functions: it generates the first control signal responsive to the input clock signal, controls the latch circuit and memory state trigger circuit based on the first control signal, and ensures proper timing synchronization. By making this single circuit multi-functional, the design achieves high reliability without proportionally increasing overall complexity.
Solution Approach 2:
The circuit merges the enable signal latching function, clock signal generation function, and timing control function into a unified architecture where the latch circuit, memory state latch circuit, and trigger circuits work together as an integrated system. This merging reduces the need for separate control paths while maintaining reliability through the coordinated operation of unified components.
Data Source
AI summary
A clock circuit includes a latch circuit, a memory state latch circuit, a first inverter, a memory state trigger circuit and a second inverter. The latch circuit is configured to latch an enable signal, and to generate a latch output signal based on a first clock signal and a first output clock signal. The memory state latch circuit is configured to latch a second output clock signal responsive to a third output clock signal. The first inverter is configured to generate the first output clock signal responsive to the third output clock signal. The memory state trigger circuit is configured to generate the second output clock signal responsive to the latch output signal. The second inverter is configured to generate the first clock signal responsive to a second clock signal, and configured to control the latch circuit and the memory state trigger circuit based on the first clock signal.