Address Stream Data Embedding for Complete Memory Trace Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The complexity of modern memory devices makes it challenging to perform accurate signal-trace-analysis during memory testing, as existing logic analyzers have limited input channels and require excessive probes and storage to trace both address and data streams simultaneously, leading to undiscoverable data or control dependencies.
Innovation Solution
A method to embed data directly or indirectly within the address stream using a hidden channel, allowing context and control dependencies to be recorded without additional hardware, thereby enhancing memory-system simulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If logic analyzers trace both address and data streams simultaneously using excessive probes and storage, then measurement completeness is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts only the necessary data (control dependencies and selected data dependencies) from the full data stream and embeds them into the address stream. This allows the logic analyzer to trace control flow information without needing to capture and process the entire data stream, thereby reducing the number of probes and storage requirements while maintaining measurement completeness for control dependencies.
Solution Approach 2:
The address stream is made multi-functional by embedding both address information and control dependency information within the same signal channel. This allows a single logic analyzer input channel to capture both traditional address tracing and control flow analysis, eliminating the need for separate instrumentation for control dependency tracking.
2Measurement precision
If logic analyzers use excessive probes and storage to trace both streams, then measurement completeness is improved, but loss of substance increases
Solution Approach 1:
The patent extracts only the essential control dependency information from the data stream and places it in the address stream. This extraction approach means that storage is only needed for the compact address stream containing embedded control information, rather than storing separate, potentially massive data streams. The result is dramatically reduced storage requirements while maintaining complete control dependency measurement.
3Measurement precision
If additional instrumentation is used to trace data stream, then measurement completeness is improved, but ease of operation worsens
Solution Approach 1:
The patent merges control dependency information with the address stream, allowing both address tracing and control flow analysis to be performed through a single logic analyzer configuration. This consolidation eliminates the operational complexity of setting up and synchronizing multiple separate instrumentation channels, making the testing process easier to operate while maintaining complete measurement capability.
Data Source
Figure 1
Figure 2-1
Figure 2-2
AI summary
Techniques and devices are described for embedding data in an address stream on an interconnect, such as a memory bus. Addresses in an address stream indicate at least part of a location in memory (e.g., a memory page and offset), whereas data embedded in the address stream can indicate when metadata or other information is available to lend context to the addresses in the address stream. The indication of data in the address stream can be communicated using, for example, a mailbox, a preamble message in a messaging protocol, a checksum, repetitive transmission, or combinations thereof. The indication of data can be recorded from the address stream and may later be used to interpret memory traces recorded during a test or can be used to communicate with a memory device or other recipient of the data during testing or regular operations.