Difference between revisions of "InOrder Resource-Request Model"
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== Defining Your Own Resources == | == Defining Your Own Resources == | ||
| + | The easiest way to define your own resource is to find a resource that is similar to what you are trying to create, and then use that as a template for your design. | ||
| + | |||
| + | More specifically, you'll need to derive from the "Resource" class and then define your own resource-specific "execute" function. In the simplest case, where your | ||
| + | resource is of zero (same-cycle) latency, then this should do the trick. If you resource processes requests on multiple cycles, then a good example of that is | ||
| + | the instruction buffer, the caches, or the multiply/divide units. | ||
| + | |||
| + | Also note, for an instruction to use your resource, you need to : | ||
| + | # Add the resource to the resource pool | ||
| + | # Add the resource to that instruction's instruction schedule | ||
Revision as of 13:29, 19 January 2010
Contents
Overview
Resources consists of any CPU object that an instruction wants to access. This could be a branch predictor, a cache, a execution unit, etc. In the InOrder CPU model we abstract what a resource is into a generic "Resource" class that all specific resources must derive from. In any given pipeline stage, an instruction will request that a resource perform a specific operation on it's behalf. If an instruction can complete all it's resource requests for a given stage, then it may pass to the next stage.
Relevant source files:
- resource.[hh,cc]
- resources/*.[hh,cc]
- pipeline_traits.[hh,cc]
- cpu.[hh,cc]
Resource-Request Model
Resource Internals
Slots
Execute
Predefined Resources
The following pipeline resources are defined for InOrderCPU:
- Fetch Unit
- Instruction Cache (I-Cache)
- Branch Prediction Unit (BPred Unit)
- Register File Manager (RF Manager)
- Address Generation Unit (AGen Unit)
- Execution Unit (EXU)
- Integer Multiply and Divide Unit (Int MDU)
- Data Cache (D-Cache)
- Graduation Unit (Grad Unit)
Defining Your Own Resources
The easiest way to define your own resource is to find a resource that is similar to what you are trying to create, and then use that as a template for your design.
More specifically, you'll need to derive from the "Resource" class and then define your own resource-specific "execute" function. In the simplest case, where your resource is of zero (same-cycle) latency, then this should do the trick. If you resource processes requests on multiple cycles, then a good example of that is the instruction buffer, the caches, or the multiply/divide units.
Also note, for an instruction to use your resource, you need to :
- Add the resource to the resource pool
- Add the resource to that instruction's instruction schedule
