Open Drain Bus Slave Identification via Iterative Bit Grouping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional serial communication protocols, such as I2C, cannot manage response conflicts when multiple slave circuits respond simultaneously over an open drain bus, making it difficult to identify slaves without initial addressing.
Innovation Solution
A method and device that use an open drain serial protocol inventory to iteratively recognize slave modules by testing identifier bits in groups, allowing simultaneous communication and identification of slaves without addressing constraints, using packets of 2p-bit digital words to determine the priority logic state and reconstructing digital information items step-by-step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional serial protocols (e.g., I2C) are used for communication between master and slaves, then the protocol is simple and widely compatible, but response conflicts occur when multiple slaves respond simultaneously and slaves cannot be identified without initial addressing
Solution Approach 1:
The patent segments the slave identification process into iterative groups of p bits. Instead of transmitting complete identifiers at once, the system tests p bits at a time, with each iteration narrowing down the possible slave identifiers. This segmentation allows the master to identify slaves progressively without requiring complex addressing mechanisms, resolving the contradiction between identification capability and protocol complexity.
Solution Approach 2:
The patent introduces dynamic response management where slaves respond simultaneously based on their identifier bits, and the master dynamically processes these responses to identify slaves. The system adapts the number of iterations and bit groups based on the actual number of slaves present, making the protocol flexible and capable of handling varying numbers of slaves without predefined addressing constraints.
2Adaptability or versatility
If multiple slaves respond simultaneously over the open drain bus, then the bus can support unlimited known or unknown slaves, but response conflicts make it difficult to manage and identify slaves
Solution Approach 1:
The patent implements a feedback mechanism where the master sends test patterns for groups of p bits, and slaves respond based on their identifiers. The master uses these responses as feedback to determine which slaves are present on the bus. This iterative feedback process allows reliable identification of multiple slaves simultaneously, resolving the response conflict issue while maintaining the ability to support unlimited slaves.
Solution Approach 2:
The patent performs preliminary testing of p-bit groups before complete identifier transmission. By pre-testing smaller bit groups and using the results to guide subsequent iterations, the system efficiently manages simultaneous slave responses. This preliminary action allows the master to progressively narrow down slave identifiers without all slaves responding at once with complete information, reducing response conflicts.
3Ease of operation
If iterative recognition of slave identifiers is performed, then slaves can be identified without initial addressing, but the process requires multiple iterations and processing time
Solution Approach 1:
The patent applies partial action by testing only p bits at a time rather than complete identifiers in a single operation. This partial testing reduces the complexity of each iteration and allows for more efficient processing. The system can stop early if the number of slaves is known, avoiding unnecessary iterations and reducing overall recognition time while maintaining ease of operation.
Solution Approach 2:
The patent changes the parameter of identifier testing from complete identifiers to groups of p bits. This parameter change allows the system to reduce the processing load in each iteration while maintaining the ability to uniquely identify slaves. By adjusting the size of bit groups and the number of iterations based on the actual number of slaves, the system optimizes recognition time without sacrificing ease of operation.
Data Source
AI summary
According to one implementation, the slave identifier bits are tested recursively in groups of p bits. For these p bits, each slave will recognize, in its p corresponding identifier bits, one combination out of the 2p possible combinations. The slaves respond simultaneously (20) over the bus, for example an I2C bus, to a request from the master. The response is given by outputting a series of “1” bits in which each slave inserts a “0”, which is, for example, the priority logic value on the bus, the position of the “0” in the series of “1” bits being dependent on the binary value of the combination recognized by the slave in the group of p bits of its identifier. The master progressively determines on the fly, based on the bits of the frame received, the values of bits of these digital information items.