Vehicular CAN Buffer Management with State Signs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicular communication devices using the CAN protocol struggle with efficient simultaneous reception and transmission of data in full duplex communication, as the ring buffer structure is not effectively utilized in these scenarios.
Innovation Solution
The implementation of a vehicular communication device with multiple buffers having a ring structure, where each buffer is assigned state signs indicating its operational state, allowing for efficient selection and use based on the communication state, enabling common storage of reception and transmission data and effective memory utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a single ring buffer is used for both reception and transmission data, then memory area is saved, but the buffer cannot be properly used for full duplex communication simultaneously executing reception and transmission
Solution Approach 1:
The single ring buffer is segmented into multiple virtual buffers through the use of state signs. Each state sign (idling, receiving, transmitting) represents a distinct operational segment, allowing the buffer to be logically divided into reception and transmission regions without requiring physical separation. This enables full duplex communication by assigning different state signs to different buffer regions, while still utilizing the same physical memory area.
2Adaptability or versatility
If separate buffers are allocated for reception and transmission in full duplex communication, then simultaneous reception and transmission can be executed, but total memory size increases
Solution Approach 1:
The ring buffer is designed with multi-functionality to serve both reception and transmission purposes simultaneously. By introducing state signs that can be set to different values (idling, receiving, transmitting), the same buffer structure can adapt to different operational modes. This universal design allows the buffer to function as either reception buffer or transmission buffer depending on the state sign, eliminating the need for separate dedicated buffers while maintaining full duplex capability.
3Reliability
If state signs are introduced to manage buffer states, then accurate buffer selection is enabled, but device complexity increases
Solution Approach 1:
Instead of implementing a complex global buffer management system, the patent applies local quality by attaching state signs directly to individual buffer regions. Each buffer region has its own state sign that independently indicates its operational state. This localized approach simplifies management because each state sign can be handled independently, and the selection logic only needs to check the state sign of the specific buffer region being accessed, rather than managing complex interdependencies across the entire buffer system.
Data Source
AI summary
An electronic control unit (ECU) and a tester are connected to exchange a CAN message through full duplex communication. A CAN communication control unit included in the ECU executes processings such as CAN message reception, response data generation, and CAN message transmission. A buffer management unit included in the ECU is equipped with a plurality of buffers that has uninterrupted ring address structure. The buffer stores reception and transmission data in common with a state sign. The state sign is attached by the CAN communication control unit to indicate a state currently executed in the buffer. The CAN communication control unit selects to use one of the buffers based on the state sign of the buffer when the reception of the request data or the transmission of the response data is executed.