Dual-Port Electronic Device Bus Reset Interference Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The IEEE 1394 standard's bus reset mechanism disrupts data transfer during content protection, particularly when nodes are added or removed, leading to repeated key exchanges and increased CPU load, causing interruptions in encryption decoding and traffic congestion.
Innovation Solution
An electronic device with dual ports and processing means that selectively operates in modes to manage bus connections, allowing independent operation of physical and link layers, and controlling bus reset signals to minimize interference and maintain continuous data transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If bus reset mechanism is implemented to manage node changes, then node addition/removal is handled, but data transfer is interrupted and CPU load increases
Solution Approach 1:
The bus system is segmented into multiple independent buses. When a reset is needed on one bus due to node changes, other buses can continue data transfer without interruption. This segmentation isolates the impact of bus resets to specific segments rather than affecting the entire system.
Solution Approach 2:
A bus switch acts as an intermediary device that can redirect data flow between different buses. When one bus experiences a reset, the bus switch can reroute traffic through alternative buses, maintaining data transfer continuity and preventing system-wide interruptions.
2Adaptability or versatility
If bus reset occurs during content protected data transfer, then node changes are recognized, but encryption key exchange is disrupted and decoding fails
Solution Approach 1:
The encryption key exchange is completed and established before any bus reset operations occur. By performing the key exchange in advance and maintaining it across bus resets, the content protection integrity is preserved even when node changes trigger bus resets. The key exchange is decoupled from the bus reset timing.
3Adaptability or versatility
If multiple bus reset cycles occur consecutively, then bus parameters are optimized, but AKE is repeatedly stopped and encryption key cannot be ensured
Solution Approach 1:
The encryption key exchange process is designed to continue uninterrupted across multiple bus reset cycles. Rather than restarting AKE with each reset, the system maintains the key exchange state and resumes data transfer after resets complete, ensuring continuous useful action without repeated time loss.
4Adaptability or versatility
If bus reset signal is generated for node changes, then node information is updated, but traffic congestion occurs and CPU load increases
Solution Approach 1:
The system segments node information updates to occur on individual buses rather than triggering system-wide resets. This allows node information to be updated locally on affected buses while other buses maintain normal data transfer operations, preventing traffic congestion and reducing overall CPU load.
Data Source
AI summary
This invention provides an electronic device that can suppress the undesired influence of signals flowing on the bus as interference on devices connected to the bus. The electronic device has two ports connected to the bus with corresponding physical layer processing means. The physical layer processing means may optionally be connected together permitting separate connection to separate busses. Thus a bus reset on first bus will not interfere with processing on the second bus.