Pipeline NOP Insertion for Shared Memory Access Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pipeline processing efficiency is reduced due to synchronization displacement of data paths when shared memory is accessed, causing pipeline stalls and requiring restarts of partially executed instructions.
Innovation Solution
An instruction insertion controller is used to insert no-operation instructions or detect embedded no-operation instructions in the control program, allowing the pipeline processing unit to continue execution without interruption by correcting relative displacement of control information between stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pipeline processing unit continues execution without stopping when shared memory is accessed, then processing efficiency is maintained, but data path synchronization displacement occurs causing hazards
Solution Approach 1:
The instruction insertion controller detects memory access requests from general-purpose processors before the pipeline completes its current instructions, and proactively inserts NOP instructions into the pipeline. This preliminary action prevents synchronization displacement hazards before they occur, allowing the pipeline to continue execution without full stalls while maintaining data path integrity.
Solution Approach 2:
NOP (no-operation) instructions serve as intermediary elements inserted into the pipeline instruction stream. These NOP instructions act as buffers that absorb the timing discrepancy between pipeline execution and external memory access, allowing data to be properly synchronized without stopping the entire pipeline. The NOP instructions fill the time gap without consuming computational resources.
2Reliability
If the pipeline is stopped to allow shared memory access, then data synchronization is maintained, but processing efficiency deteriorates due to pipeline stalls and instruction restarts
Solution Approach 1:
The system proactively inserts NOP instructions before the pipeline would naturally stall, allowing continuous execution flow. By preparing the pipeline with NOP placeholders in advance, the system avoids the overhead of detecting hazards, stopping, and restarting instructions, thereby maintaining high processing efficiency while ensuring data synchronization.
Solution Approach 2:
The pipeline processing unit maintains continuous operation by inserting NOP instructions that preserve the instruction flow. Instead of stopping the pipeline and losing the momentum of parallel processing, the NOP instructions allow the pipeline to continue advancing through its stages, keeping all processing units actively engaged and maintaining throughput.
3Productivity
If NOP instructions are inserted to accommodate memory access requests, then pipeline continuity is maintained, but control information displacement occurs between stages
Solution Approach 1:
The instruction insertion controller acts as an intermediary between the instruction fetch unit and the pipeline stages. It intercepts the instruction stream, inserts NOP instructions at appropriate locations, and manages the control information flow. This centralized control mechanism handles the complexity of tracking and adjusting control signals for inserted NOPs, preventing dispersion across multiple pipeline stages.
Solution Approach 2:
The instruction insertion controller monitors memory access requests from general-purpose processors and uses this feedback to determine where NOP instructions should be inserted. By continuously observing the timing and nature of external memory accesses, the controller dynamically adjusts the insertion points of NOP instructions, ensuring proper synchronization without manual intervention or complex pre-programming.
Data Source
AI summary
A pipeline operation processor comprises a pipeline processing unit and an instruction insertion controller which inserts an instruction when access to an operation memory is requested, and corrects control information by reference to control information of stages. When a control program is in execution, on receiving an access request instruction requesting for access to the operation memory, the instruction insertion controller inserts an NOP instruction from the instruction decoding unit in place of the access request instruction. The access request instruction is executed while the pipeline processing unit executes no operation, and subsequently, the pipeline processing is continued.