5.7.2 Functional Unit Performance

 

• These timings are typical for other proces- sors as well.
• Each operation is characterized by its latency, meaning the total time required to perform the operation
• the issue time, meaning the minimum number of clock cycles between two independent operations of the same type
• the capacity, indicating the number of functional units capable of performing that operation.
• This short issue time is achieved through the use of pipelining.
• What this means is that the divider must perform a complete division before it can begin a new one.
• Having multiple functional units can increase throughput even further.
•  

 

5.7.3 An Abstract Model of Processor Operation

 

• As a tool for analyzing the performance of a machine-level program executing on a modern processor, we will use a data-flow representation of programs, a graphical notation showing how the data dependencies between the different operations constrain the order in which they are executed.