Status: Tags: #cards/cmpt295/mp Links: Microprocessor
Microprocessor Superscalar Execution
Principles
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- Modern microprocessors have instruction level parallelism
- Have multiple functional units, which can be assigned one instruction per clock cycle
- Operation results is shared bus that goes back into register file
- Output of codes are added together and converted into proper intention of machine code
Out of Order Execution (OoOE)
- Rearrange execution order of instructions to:
- Avoid hazards
- maximize use of functional units
- How:
- Instruction Control Unit (ICU) fetches machine level instructions from memory (instruction cache)
- Decodes and analyzes for data dependencies (hazards)
- Avoids hazards by running eligible micro-operations by Execution Unit (EU)
- Each clock cycle
- Retirement Unit of ICU “puts everything back in order” to resemble sequential execution
References:
Created:: 2022-04-08 02:30