Multi-Power-Domain Signal Path Stabilization During Power-Off
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Solution Overview
Problem
Integrated circuits with multiple power domains face interference issues when one domain is powered off, as existing isolation cells cannot be enabled at the correct time, leading to signal disruption or prevention of signal transmission between domains.
Innovation Solution
A weakly pull circuit is introduced to maintain the transmission path at a stable logic level when a power domain is in a power-off mode, preventing unknown signals from entering other domains and ensuring continuous operation without the need for an isolation cell or advanced power-off timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an isolation cell is disposed between power domains to prevent noise interference, then noise protection is improved, but signal transmission capability deteriorates when the isolation cell is enabled too early
Solution Approach 1:
The isolation cell's enable state is made dynamic rather than static. The enable signal is generated based on real-time detection of power domain states through the weakly pull-down circuit, allowing the isolation cell to adapt its state according to actual operating conditions rather than being fixed in advance.
Solution Approach 2:
A feedback mechanism is implemented where the weakly pull-down circuit continuously monitors the power domain state and generates an enable signal that feeds back to control the isolation cell. This closed-loop control ensures the isolation cell is enabled only when actually needed, preventing both noise interference and unnecessary signal blocking.
2Productivity
If an isolation cell is enabled too late to prevent noise interference, then signal transmission is maintained, but noise interference occurs in the power-on domain
Solution Approach 1:
The weakly pull-down circuit is pre-configured to detect power domain states and prepare the enable signal in advance. When a power domain transitions to the off state, the circuit immediately detects this change and generates the corresponding enable signal for the isolation cell, ensuring timely activation without delay.
Solution Approach 2:
The system uses its own internal state information (power domain on/off status) to automatically control the isolation cell through the weakly pull-down circuit. No external control or manual timing adjustment is needed; the system self-regulates the isolation cell's enable state based on its own operating conditions.
3Object-affected harmful factors
If isolation cells are used to prevent interference between power domains, then noise protection is improved, but device complexity increases
Solution Approach 1:
The weakly pull-down circuit serves as an intermediary between the power domains and the isolation cell. Instead of directly controlling the isolation cell or requiring complex configuration, this intermediate circuit automatically generates the appropriate enable signal based on power domain states, simplifying the overall control mechanism.
Solution Approach 2:
The isolation cell configuration becomes self-adjusting through the weakly pull-down circuit's automatic enable signal generation. The system eliminates the need for manual timing configuration or complex control logic, as the isolation cell automatically receives the correct enable signal based on real-time power domain states.
Data Source
AI summary
An integrated circuit and a signal transmission method thereof are provided. The integrated circuit includes a first power domain, a second power domain, and a weakly pull circuit. The first power domain is powered by a first power source, the second power domain is powered by a second power source, and the second power domain transmits a signal to the first power domain through a transmission path. The weakly pull circuit is signally connected to the transmission path. When the second power domain is in a power-off mode, the weakly pull circuit maintains the transmission path stably at a logic level to prevent unknown signals from entering the first power domain from the second power domain and disturbing the normal operation of the first power domain.