Semiconductor Memory Comparison Circuit Reducing CPU Load

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Solution Overview

Problem

Existing semiconductor integrated circuit devices face inefficiencies in data comparison processes, particularly due to the long time required for comparison results using CPU instructions and the limited comparison capabilities of hardware-based systems, which restrict processing speed and load on CPUs.

Innovation Solution

A semiconductor integrated circuit device with a memory comparison circuit configured as dedicated hardware, capable of comparing data sets using DMA transfer and interrupt mechanisms, allowing for various comparison conditions and error allowances, thereby reducing CPU load and enhancing processing speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If comparison is performed using CPU comparison instructions, then arbitrary comparison types (simple comparison, comparison allowing error) can be carried out, but the time required to obtain comparison result is relatively long

Engineering Contradiction:
Improvecomparison type flexibilityVSAvoidcomparison execution time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The invention divides the comparison function into two segments: a dedicated hardware comparison circuit for fast execution of specific comparison operations, and the CPU for handling arbitrary comparison types. This segmentation allows the system to use the fastest method for common comparisons while retaining CPU flexibility for special cases.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a dedicated comparison circuit as an intermediary between the CPU and data storage. This intermediary handles the time-consuming comparison operations independently, freeing the CPU from execution delays while maintaining the ability to perform various comparison types through programmed control of the comparison circuit.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If dedicated hardware comparison circuit is used, then processing speed is enhanced and CPU load is reduced, but comparison method is limited to coincidence check only

Engineering Contradiction:
Improveprocessing speedVSAvoidcomparison method variety
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The invention makes the dedicated comparison circuit multi-functional by enabling it to perform not only coincidence checks but also comparisons allowing errors, simple comparisons, and other comparison types. The comparison circuit can be programmed to execute different comparison operations, combining hardware speed with software flexibility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention makes the comparison circuit dynamic by allowing its comparison mode to be changed through programming. The circuit can adapt its comparison method based on the specific task requirements, switching between coincidence check, error-tolerant comparison, and other modes as needed, thus maintaining both speed and versatility.

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple CPUs perform same processing and output data to memory, then reliability can be improved through collation, but processing load on memory and complexity of system increases

Engineering Contradiction:
Improvedata accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the collation function from the CPUs and memory system by implementing a dedicated comparison circuit. Multiple CPUs can still perform the same processing and output to memory, but the comparison and collation operations are handled by the specialized hardware circuit, reducing memory access requirements and system complexity while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3457292B1Semiconductor integrated circuit device and data comparing method
Publication Date: 2020.10.07 RENESAS ELECTRONICS CORP
  • EP3457292B1 patent drawingFigure 1
  • EP3457292B1 patent drawingFigure 2
  • EP3457292B1 patent drawingFigure 3(a)~3(b)

AI summary

Data on a memory space are compared without using a CPU, and an interrupt is generated in an interrupt condition based on at least one of the number of times of the comparison and the number of times of coincidence with a comparison condition. An interrupt controller outputs an interrupt signal to a first CPU core or a second CPU core. A DMAC transfers data on the memory space to at least one of a first buffer and a second buffer. A comparison circuit compares the data of the first buffer with the data of the second buffer. A condition coincidence frequency counter counts the number of times at which the comparison in the comparison circuit coincides with a comparison condition. An interrupt request circuit outputs an interrupt request to the interrupt controller, based on at least one of a value of the condition coincidence frequency counter and a value of a comparison frequency counter.