Parallel Computer Organization & Design —
Lecture Slides for All 8 Chapters (PDF)
Briefly characterize Amdahl's law. - answer-Using multiple processors will provide increase in
speed at a diminishing rate. Also provides little return on small amounts of code.
Briefly explain Moore's law - answer-Number of transistors in a cpu doubles approximately
every two years.
In virtually all systems that include DMA modules, DMS to main memonry is given higher
priority that CPU access to main memory. Why? - answer-If the CPU is held up no data loss will
occure, the DMS could, so it takes priority.
What is the function of condition codes? - answer-Condition codes are bits set by the CPU
hardware as the result of operations
What is a program status word? - answer-A register contains condition codes and status
information.
Why is a two-stage instruction pipeline unlikely to cut the instruction cycle time in half,
compared with the use of no pipeline? - answer-Either way there may be wait time for things to
be fetched
How are history bits used for branch prediction? - answer-Indicators that direct the processor to
make a particular decision.
Briefly explain the two basic approaches used to minimize register-memory operations on RISC
machines. - answer-● Use of algorithms and the compiler to maximize register usage
1
, ● Use more registers so that more variables can be held in registers for longer.
What is a delayed branch? - answer-Delayed branch, a way of increasing the efficiency of the
pipeline, makes use of a branch that does not take effect until after execution of the following
instruction.
What is the essential characteristic of the superscalar approach to processor design? - answer-
Can execute multiple independent instructions in parallel.
What is instruction-level parallelism? - answer-Tells how many instructions in a program can be
executed in
What is the purpose of an instruction window? - answer-A buffer which allows out-of-order
issue to decouple the Decoding stage and Execution stage
What is register renaming and what is its purpose? - answer-Is a technique in pipelining concept
which makes use of Data dependencies between the instructions by renaming operand
registers. Eliminates WAR WAW dependencies.
If a circular register buffer is used to handle local variables for nested procedures, describe two
approaches for handling global variables. - answer-● Assign them to memory locations by the
compiler, and then instructions will use memory-reference operands.
● Use a set of global registers.
What categories of data are commonly supported by user-visible registers? - answer-● General
Purpose
● Data
● Adress
2
Lecture Slides for All 8 Chapters (PDF)
Briefly characterize Amdahl's law. - answer-Using multiple processors will provide increase in
speed at a diminishing rate. Also provides little return on small amounts of code.
Briefly explain Moore's law - answer-Number of transistors in a cpu doubles approximately
every two years.
In virtually all systems that include DMA modules, DMS to main memonry is given higher
priority that CPU access to main memory. Why? - answer-If the CPU is held up no data loss will
occure, the DMS could, so it takes priority.
What is the function of condition codes? - answer-Condition codes are bits set by the CPU
hardware as the result of operations
What is a program status word? - answer-A register contains condition codes and status
information.
Why is a two-stage instruction pipeline unlikely to cut the instruction cycle time in half,
compared with the use of no pipeline? - answer-Either way there may be wait time for things to
be fetched
How are history bits used for branch prediction? - answer-Indicators that direct the processor to
make a particular decision.
Briefly explain the two basic approaches used to minimize register-memory operations on RISC
machines. - answer-● Use of algorithms and the compiler to maximize register usage
1
, ● Use more registers so that more variables can be held in registers for longer.
What is a delayed branch? - answer-Delayed branch, a way of increasing the efficiency of the
pipeline, makes use of a branch that does not take effect until after execution of the following
instruction.
What is the essential characteristic of the superscalar approach to processor design? - answer-
Can execute multiple independent instructions in parallel.
What is instruction-level parallelism? - answer-Tells how many instructions in a program can be
executed in
What is the purpose of an instruction window? - answer-A buffer which allows out-of-order
issue to decouple the Decoding stage and Execution stage
What is register renaming and what is its purpose? - answer-Is a technique in pipelining concept
which makes use of Data dependencies between the instructions by renaming operand
registers. Eliminates WAR WAW dependencies.
If a circular register buffer is used to handle local variables for nested procedures, describe two
approaches for handling global variables. - answer-● Assign them to memory locations by the
compiler, and then instructions will use memory-reference operands.
● Use a set of global registers.
What categories of data are commonly supported by user-visible registers? - answer-● General
Purpose
● Data
● Adress
2
