3-Stage Pipeline - 2024.1 English - UG1629

MicroBlaze V Processor Reference Guide (UG1629)

Document ID
UG1629
Release Date
2024-05-30
Version
2024.1 English

With C_OPTIMIZATION set to 1 (area), the pipeline is divided into three stages to minimize hardware cost: Fetch, Decode, and Execute.

Table 1. 3-Stage Pipeline
  Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 6 Cycle 7  
Instruction 1 Fetch Decode Execute          
Instruction 2   Fetch Decode Execute Execute Execute    
Instruction 3     Fetch Decode Stall Stall Execute  
                 

The 3-stage pipeline does not have any data hazards. Pipeline stalls are caused by control hazards, structural hazards due to multi-cycle instructions, memory accesses using slower memory, instruction fetch from slower memory, or stream accesses.

The multi-cycle instruction categories are multiply, divide, remainder, and floating-point instructions.