Deterministic Serial Bus Transactions via Arbitration Delay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Serial bus protocols like SPMI are non-deterministic in timing due to variable length arbitration, preventing their use for components requiring deterministic timing, such as RFFE components, which often necessitate separate ICs or buses, increasing cost and pin requirements.
Innovation Solution
Implementing a method to determine a delay period based on the arbitration phase length, ensuring commands are sent over the serial bus at a specific time, allowing for deterministic transactions without additional buses or pins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a standard serial bus protocol like SPMI is used with arbitration process, then multiple masters can communicate with multiple slaves, but the timing becomes non-deterministic
Solution Approach 1:
The transaction is segmented into distinct phases: arbitration phase and execution phase. The arbitration phase handles master selection non-deterministically, while the execution phase operates deterministically with a fixed delay period, separating the non-deterministic and deterministic aspects of the communication
Solution Approach 2:
The delay period is determined in advance based on the arbitration phase length before the actual command execution begins. This preliminary timing calculation ensures that the execution phase starts at a predictable time point, making the overall transaction deterministic despite the variable arbitration phase
2Reliability
If RFFE components are placed on a separate IC or require a separate deterministic bus, then deterministic timing is achieved, but cost and pin requirements increase
Solution Approach 1:
The standard serial bus is made multi-functional by enabling it to support both non-deterministic transactions (with arbitration) and deterministic transactions (with fixed delay). The same bus infrastructure handles both types of communications, eliminating the need for separate deterministic buses or additional pins
Solution Approach 2:
The timing parameters of the serial bus protocol are modified by introducing a fixed delay period that is determined based on the arbitration phase length. This parameter change transforms the bus behavior from non-deterministic to deterministic for specific transactions without requiring hardware changes
Data Source
AI summary
Systems and methods are disclosed method for operating a serial interconnect of a computer system in a time deterministic manner. An exemplary method comprises that a command to be sent over the serial interconnect in a transaction is to be executed at a specific time. A delay period for the command to be sent from a master of the computer system to a slave of the computer system via the serial bus is determined, where the delay period determined based on a length of an arbitration phase of the transaction. The command is then sent to the slave of the computer system via the serial bus after the delay period.