Advanced Computer Architecture
Structural, data and control - Answer-Name the three different types of hazards
A structural hazard occurs when two (or more) instructions that are already in pipeline need the same
resource - Answer-What is a structural hazard?
A control hazard occurs when deciding on control action depends on previous instruction - Answer-What
is a control hazard?
A data hazard occurs when an instruction depends on the result of a prior instruction still in the pipeline
- Answer-What is a data hazard?
Temporal locality refers to the reuse of specific data, and/or resources, within a short time. - Answer-
What is temporal locality?
Spatial locality refers to the use of data elements within relatively close storage locations. - Answer-
What is spatial locality?
More comparators and an output multiplexer are needed - Answer-Why is an associative cache slower
than a direct mapped cache?
Because the slowest pipeline stage determines the maximum speed of the whole pipeline, and main
memory is very slow - Answer-Why are caches needed in a pipelined architecture?
, Compulsory, Capacity and Conflict - Answer-Name the three types of cache misses
AMAT = HitTime + MissRate * MissPenalty - Answer-Give an expression for the Average Memory Access
Time of a cache
1. Larger block size
2. Higher associativity
3. Use a victim buffer
4. Hardware prefetching
5. Use a skewed associative cache - Answer-Name (five) ways to reduce the cache miss rate in hardware
Compulsory - Answer-Which of the cache miss types does a larger block size reduce?
Conflict - Answer-Which of the cache miss types does higher associativity reduce?
Conflict - Answer-Which of the cache miss types does a victim buffer reduce?
Increasing associativity is considerably more complicated and expensive - Answer-Why is a victim buffer
more attractive than increasing associativity to reduce conflict misses?
Compulsory - Answer-Which of the cache miss types does hardware prefetching reduce?
Conflict - Answer-Which of the cache miss types does a skewed associative cache reduce?
Binding prefetching fetches data using a load instruction directly into a register - Answer-What is binding
software prefetching?
Structural, data and control - Answer-Name the three different types of hazards
A structural hazard occurs when two (or more) instructions that are already in pipeline need the same
resource - Answer-What is a structural hazard?
A control hazard occurs when deciding on control action depends on previous instruction - Answer-What
is a control hazard?
A data hazard occurs when an instruction depends on the result of a prior instruction still in the pipeline
- Answer-What is a data hazard?
Temporal locality refers to the reuse of specific data, and/or resources, within a short time. - Answer-
What is temporal locality?
Spatial locality refers to the use of data elements within relatively close storage locations. - Answer-
What is spatial locality?
More comparators and an output multiplexer are needed - Answer-Why is an associative cache slower
than a direct mapped cache?
Because the slowest pipeline stage determines the maximum speed of the whole pipeline, and main
memory is very slow - Answer-Why are caches needed in a pipelined architecture?
, Compulsory, Capacity and Conflict - Answer-Name the three types of cache misses
AMAT = HitTime + MissRate * MissPenalty - Answer-Give an expression for the Average Memory Access
Time of a cache
1. Larger block size
2. Higher associativity
3. Use a victim buffer
4. Hardware prefetching
5. Use a skewed associative cache - Answer-Name (five) ways to reduce the cache miss rate in hardware
Compulsory - Answer-Which of the cache miss types does a larger block size reduce?
Conflict - Answer-Which of the cache miss types does higher associativity reduce?
Conflict - Answer-Which of the cache miss types does a victim buffer reduce?
Increasing associativity is considerably more complicated and expensive - Answer-Why is a victim buffer
more attractive than increasing associativity to reduce conflict misses?
Compulsory - Answer-Which of the cache miss types does hardware prefetching reduce?
Conflict - Answer-Which of the cache miss types does a skewed associative cache reduce?
Binding prefetching fetches data using a load instruction directly into a register - Answer-What is binding
software prefetching?
