SPMI Multicast Feedback via Time-Multiplexed Slots
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional serial bus protocols, such as SPMI, lack a feedback mechanism for multicast write transactions, making it difficult to determine which devices have successfully received data or commands, as any device can drive the ACK/NACK bit, leading to unclear error sources and potential misinterpretation of transmission failures.
Innovation Solution
Implementing a feedback mechanism that uses multibit slots within data frames to allow individual devices to provide device-specific feedback, using a dummy data byte in multicast transactions to enable time-division multiplexing (TDM) feedback, where each device can acknowledge or indicate errors in specific time slots, enabling the transmitter to identify the source of issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional ACK/NACK mechanism is used on the serial bus, then transmission feedback is provided, but the source of errors cannot be identified in multicast transactions
Solution Approach 1:
The patent segments the feedback mechanism by allocating specific bit positions within the data frame to individual receiving devices. Each device is assigned unique bit positions where it can set acknowledgment or error bits, allowing the transmitting device to identify which specific receiver encountered errors. This segmentation resolves the contradiction by providing both feedback (reliability) and error source identification (information preservation) simultaneously.
2Productivity
If multiple devices are addressed by a multicast write command, then communication efficiency is improved, but feedback from individual devices becomes ambiguous
Solution Approach 1:
The patent applies local quality by giving each receiving device its own dedicated bit positions within the data frame structure. Instead of a single shared ACK/NACK line, each device has localized control over specific bits that reflect its individual reception status. This allows multicast efficiency to be maintained while feedback clarity is improved, as the transmitting device can examine specific bit positions to determine which individual receivers succeeded or failed.
3Reliability
If a feedback mechanism is added to identify error sources, then transmission reliability is improved, but protocol complexity increases
Solution Approach 1:
The patent merges the feedback mechanism with the existing data frame structure by incorporating acknowledgment and error bits directly into the data frame that is already being transmitted. Rather than adding separate feedback messages or protocols, the solution combines multiple functions (data transmission, acknowledgment, and error reporting) into a single integrated frame structure. This merging approach improves reliability through error identification while minimizing protocol complexity by reusing existing frame structures.
Data Source
AI summary
Systems, methods, and apparatus are configured to enable a receiver to provide feedback. A feedback mechanism enables a transmitting device to identify the provider of feedback for a multicast transmission, and the feedback transmitted by one or more individual receivers of the multicast transmission. A method includes receiving a multicast write command from the serial bus in a first datagram, writing a data byte received in a first data frame of the first datagram to a register address identified by the first datagram, and providing device-specific feedback regarding the first datagram in a multibit slot within the second data frame. The multibit slot is one of a plurality of sequential multibit slots defined for the second data frame. Each multibit slot in the plurality of sequential multibit slots may provide device-specific feedback from one receiving device addressed by the multicast write command.