Asymmetrical Multiprocessing Memory Bad Block Table Management
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Solution Overview
Problem
In asymmetrical multiprocessing configurations of image forming apparatuses, each control part needs to read information about defective areas in the auxiliary memory during startup, leading to delays in the boot process due to the requirement of creating separate defective area tables for each control part.
Innovation Solution
The apparatus includes a main control part and a sub-control part, with a main memory and an auxiliary memory, where each control part reads and expands the control program to the main memory to create and manage defective area tables, specifying and managing bad blocks in the auxiliary memory, thereby reducing the need for redundant area reads and accelerating the startup process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If each control part reads information about defective areas in the auxiliary memory during startup to create separate defective area tables, then the reliability of memory access is improved, but the startup time is delayed
Solution Approach 1:
The patent merges the defective area table creation process by having the first control part create a comprehensive defective area table that covers both the first use area (accessed by main control part) and the second use area (accessed by sub control part). This eliminates the need for the second control part to separately read and create its own defective area table, thereby reducing startup time while maintaining memory access reliability for both control parts.
Solution Approach 2:
The defective area table created by the first control part serves multiple functions: it protects both the first use area accessed by the main control part and the second use area accessed by the sub control part. This universal defective area table avoids redundant operations and accelerates the startup process while ensuring reliable memory access for all control parts.
2Measurement precision
If separate defective area tables are created for each control part, then the precision of defective area management is improved, but the device complexity increases
Solution Approach 1:
The patent combines the defective area management into a single comprehensive table created by the first control part, which manages both the first use area and the second use area. This approach maintains precise defective area management for both control parts while reducing system complexity by eliminating redundant table creation processes and associated control logic.
Data Source
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AI summary
Image forming apparatus 1 that shortens warm-up time is provided. Accordingly, image forming apparatus 1 is an asymmetrical multiprocessing configuration provided with auxiliary memory part 21 shared between main control part 10 and sub control part 11. Use area 300 is an area accessed by main control part 10. Use area 301 is an area accessed by sub control part 11. Use area specifying part 100 specifies for use area 300 and use area specifying part 101 specifies for use area 301, respectively, by use area specifying table 210. Defective area table making part 110 makes defective area table 200 by searching whether or not a defective area only for use area 300 and set as a defective area for the other area. Defective area table making part 111 makes defective area table 201 by searching use area 301, similarly, and set as the defective area for the other area.