Circular Debug Buffers for Real-Time Embedded System Communication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current debugging methods for embedded systems, such as semihosting and Serial Wire Output (SWO), cause significant delays by halting the target system, disrupting real-time operations and potentially leading to catastrophic failures in time-critical applications.
Innovation Solution
Implementing circular debug buffers that allow terminal output and input to be provided without halting the target system, enabling real-time or near-real-time communication between the target and host systems through a debug probe, which writes and reads messages efficiently without blocking the CPU.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semihosting or Serial Wire Output (SWO) is used for debugging, then debugging functionality is provided, but significant delays are caused by halting the target system
Solution Approach 1:
The patent segments the debugging communication into two independent circular buffers: an up buffer for target-to-host communication and a down buffer for host-to-target communication. This segmentation allows the target system to write debug messages to the up buffer without halting, while the debug probe reads from the down buffer separately, eliminating the need to halt the target system for debugging operations.
Solution Approach 2:
The patent introduces circular buffers as intermediary data structures stored in the target system's memory. These buffers act as mediators between the target CPU and the debug probe, allowing asynchronous communication. The target system writes to the up buffer while the debug probe reads from the down buffer, enabling real-time debugging without halting the target system.
2Ease of operation
If the target system is halted for debugging operations, then debugging control is achieved, but real-time operations are disrupted
Solution Approach 1:
The patent implements dynamic buffering where the circular buffers can be configured with different sizes and the debug probe can control the buffering mode (blocking vs. non-blocking). This allows the system to adapt between different debugging needs while maintaining real-time operation, as the buffers dynamically manage the flow of debug information without requiring system halts.
Solution Approach 2:
The patent enables continuous debugging operation through the circular buffer mechanism. The target system can continuously write debug messages to the up buffer without interruption, and the debug probe continuously reads from the down buffer. This continuous data exchange eliminates the need to halt the target system, maintaining both debugging control and real-time operation simultaneously.
3Speed
If circular debug buffers are implemented, then real-time communication is enabled, but device complexity increases
Solution Approach 1:
The patent implements self-service buffer management where the circular buffers automatically handle data exchange between the target and host. The buffers are configured with write and read pointers that automatically advance as data is written and read, eliminating the need for complex manual buffer management. The debug probe can configure the buffers and then operates autonomously, reducing the complexity burden on the target system.
Data Source
AI summary
One or more circular debug buffers can allow terminal output data to be provided from the target system to a host without halting the target system or causing significant delays. One or more circular debug buffers may also allow input (such as keyboard input) to be provided from the host to the target without halting the target system or causing significant delays. Accordingly, communications between the target and host may be performed in real time or near real time. These communications may be used for debugging purposes or more generally, for any purpose, including purposes unrelated to debugging.