Out-of-Range Reference Detection via Mask Value Storage
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Solution Overview
Problem
Existing out-of-range reference detection methods in segmented memory management systems are inefficient due to the need to search segment tables, which can be time-consuming, especially in complex configurations or multi-process environments, leading to increased memory access times.
Innovation Solution
An out-of-range reference detection device and method that utilize a mask value storage unit to directly acquire and determine whether an effective address is outside a predetermined memory range without needing to identify segment numbers or search segment tables, by using a mask value corresponding to the base address register number to quickly assess if an address is within the referable range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If segment table search method is used to detect out-of-range reference, then detection accuracy is maintained, but processing time increases significantly
Solution Approach 1:
The patent pre-calculates and stores mask values in a mask value storage unit before actual reference detection is needed. These mask values represent the valid address ranges for different base address registers and are prepared in advance, allowing rapid retrieval during out-of-range reference detection without needing to search segment tables at execution time.
Solution Approach 2:
The patent extracts the essential information needed for out-of-range reference detection (the mask values representing valid address ranges) from the complex segment table structure. By separating and storing only the necessary mask values in a dedicated storage unit, the system eliminates the need to search through the entire segment table during detection, thereby reducing processing time while maintaining accuracy.
2Measurement precision
If segment table search is performed for each process in multi-process environment, then correct segment size is acquired, but memory access time increases
Solution Approach 1:
The patent pre-calculates and stores mask values for all base address registers in the mask value storage unit before multi-process execution begins. This preliminary preparation ensures that when processes need to perform out-of-range reference detection, the required mask values are already available in fast storage, eliminating the need to access and search segment tables during process execution.
Solution Approach 2:
The patent creates a simplified copy of the segment table information in the form of mask values stored in the mask value storage unit. Instead of working with the full segment table structure that requires complex searching, the system uses these pre-computed mask value copies that contain only the essential range information needed for detection, significantly reducing memory access requirements.
3Reliability
If multiple segment tables are searched in complex memory management configurations, then complete segment size information is obtained, but detection speed decreases
Solution Approach 1:
The patent merges the essential mask value information from multiple segment tables into a single unified mask value storage unit. This consolidation combines the range information that would otherwise be scattered across multiple tables into one centralized storage structure, allowing the system to retrieve all necessary mask values in a single operation rather than searching through multiple separate tables sequentially.
Solution Approach 2:
The patent extracts the critical mask value information from the complex multi-table segment management structure and isolates it in a dedicated mask value storage unit. By separating only the necessary range detection information from the rest of the segment table structures, the system maintains complete segment size information while eliminating the need to search through multiple complex tables during detection operations.
Data Source
AI summary
An out-of-range reference detection method according to an exemplary aspect of the invention includes: acquiring a mask value corresponding to a base address register number of a predetermined effective address from a mask value storage unit storing correspondence relationships between the base address register number of a base address register storing a base address of a segment and the mask value showing a size of a memory that can be continuously referred to from the base address, determining whether or not the effective address is outside the range of the mask value, and outputting a result of the determination.