Bus Ownership Transfer via Embedded Request Packets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-master/slave systems face challenges in seamlessly transferring bus ownership between devices without requiring additional connections or processing overhead, often limited by device size and available I/O pins, and existing protocols are inefficient in facilitating this transfer.
Innovation Solution
Each master/slave device can transfer bus ownership by embedding bus ownership requests in normal response packets to master device operations, with the current master device polling slave devices at intervals to detect ownership requests, allowing for hidden polling without dedicated lines or processing overhead, and implementing various protocols for ownership transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional dedicated lines are added for bus ownership transfer, then bus ownership transfer capability is improved, but device complexity and I/O pin requirements increase
Solution Approach 1:
The patent applies universality by enabling slave devices to request bus ownership through the existing data bus response mechanism. The same bus lines used for normal data communication are also utilized for ownership requests, eliminating the need for dedicated ownership transfer lines. This multi-functional use of existing infrastructure resolves the contradiction by improving ownership transfer capability without increasing device complexity or I/O pin requirements.
Solution Approach 2:
The patent merges the bus ownership request function with the existing data response protocol. Slave devices embed ownership requests within their normal response packets to the master device, combining two functions (data response and ownership request) into a single communication mechanism. This merging approach allows bus ownership transfer without additional dedicated lines, resolving the technical contradiction.
2Difficulty of detecting and measuring
If polling mechanism is implemented for ownership requests, then bus ownership transfer detection is improved, but processing overhead increases
Solution Approach 1:
The patent applies self-service by having slave devices proactively send ownership requests within their normal response protocol without requiring active polling by the master device. The slave device initiates the ownership request mechanism itself during its response cycle, eliminating the need for master device polling processing. This resolves the contradiction by improving ownership detection capability while avoiding the processing overhead associated with polling.
Solution Approach 2:
The patent implements preliminary action by having slave devices prepare and embed ownership requests within their response packets before the master device needs to make ownership decisions. The ownership request is prepared in advance during the normal response generation process, allowing the master device to handle ownership transfer without additional polling operations or processing overhead.
3Adaptability or versatility
If more I/O pins are allocated for ownership transfer, then bus ownership transfer functionality is improved, but device size constraints are violated
Solution Approach 1:
The patent applies universality by making the existing data bus and I/O pins serve dual purposes: both data communication and bus ownership transfer. The same pins and communication paths used for normal data transactions are also utilized for ownership requests and responses, eliminating the need for additional I/O pins. This resolves the contradiction by enabling bus ownership transfer functionality without increasing device size or requiring more I/O pins.
Solution Approach 2:
The patent merges the ownership transfer functionality with the existing data communication infrastructure. By combining ownership requests into the response packet protocol, the system achieves bus ownership transfer functionality using the same physical resources (I/O pins, bus lines) already allocated for data communication, thus avoiding the need for additional hardware resources and respecting device size constraints.
Data Source
AI summary
A system may comprise multiple master/slave devices coupled to a common bus, where one of the devices may operate as the current master device and the other devices may operate as current slave devices. Current slave devices may embed bus ownership request information within response packets transmitted in response to standard bus operations, such as reads and writes, issued by the current master device. When the current master device is idle, its bus interface may continually poll the current slave devices at regular intervals, according to a specified protocol, to ascertain whether any of them are requesting bus ownership. A response to a request for bus ownership received by the current master device may be configured according to desired system functionality. In one system, ownership may always be transferred to the requesting device. In other systems, the current master device may transmit a subsequent standard bus operation request packet, or a unique response packet, either comprising embedded information indicating whether ownership of the bus has been granted.