Glitch Filter Circuit for Stable Low-Power State Transitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transitions between operational states in integrated circuits can cause glitches, leading to corruption of memory or loss of state information due to indeterminate signal states, which existing power management systems fail to adequately address.
Innovation Solution
A glitch filtering circuit is implemented using a counting circuit, flipflop, and threshold detect circuit to provide a stable representation of input signal states, suppressing transient glitches by ensuring signals remain in a consistent state for a predefined duration before propagating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If circuits are reset during transitions from low-power modes, then operational state stability is improved, but power consumption increases and transition time extends
Solution Approach 1:
The glitch filtering circuit performs preliminary filtering of input signals before they reach critical subsystems. By detecting and suppressing glitches in advance during the transition process, the circuit prevents corruption without requiring a full reset, thus maintaining reliability while reducing power consumption and transition time
Solution Approach 2:
The glitch filtering circuit acts as an intermediary between the power management system and critical subsystems. It monitors transition signals and blocks corrupted glitches from propagating to memory and control circuits, preventing corruption without triggering system-wide resets
2Reliability
If circuits are reset during transitions from low-power modes, then signal state stability is improved, but transition latency increases
Solution Approach 1:
The glitch filtering circuit performs preliminary filtering of input signals before they reach critical subsystems. By detecting and suppressing glitches in advance during the transition process, the circuit prevents corruption without requiring a full reset, thus maintaining reliability while reducing transition time
Solution Approach 2:
The circuit enables rapid transition by skipping the traditional reset sequence. The glitch filtering circuit allows valid transition signals to pass through quickly while blocking only the harmful glitches, enabling the system to rush through the transition phase without the time penalty of a complete reset
3Reliability
If glitch filtering is implemented, then data corruption is prevented, but circuit complexity increases
Solution Approach 1:
The glitch filtering function is segmented into modular components: a counting circuit for detecting signal duration, a threshold detection circuit for comparing against predefined values, and a control logic for blocking glitches. This segmentation allows the filtering function to be integrated into existing power management circuits with minimal disruption to the overall system architecture
Solution Approach 2:
The glitch filtering circuit acts as an intermediary layer between the power management system and critical subsystems. It adds a relatively simple monitoring and filtering function that prevents corruption without requiring complex system-wide changes or redesign of existing circuits
Data Source
AI summary
A glitch filtering circuit has a counting circuit configured to provide one or more counter output signals indicating whether an input signal has remained in a first signaling state or in a second signaling state for a preconfigured duration of time; a flipflop clocked by a clock signal and configured to provide an output of the glitch filtering circuit; a threshold detect circuit configured to generate a select signal based on the one or more counter output signals; and a multiplexer configured to provide a multiplexed signal to an input of the flipflop, the multiplexed signal having a signaling state that is selected in accordance with the select signal from an input fixed at the first signaling state, an input fixed at the second signaling state and an input that is coupled to the output of the glitch filtering circuit.