Test

Question 1

Difference between serial process and parallel processes

Answer 1

Serial sends a single bit at a time while parallel send multiple. Serial higher frequency, parallel lower. Serial fewer traces required, parallel more.

Question 2

What is RISC

Answer 2

Execute all instructions in a single cycle. Only read/ write to memory with load/store instructions. Requires many registers to be efficient. No microcode

Question 3

What is CISC?

Answer 3

Complicated instructions that do multiple things at once. Harder to decide and implement, required microcode. Instructions take many cycles to execute. Small number of registers

Question 4

Instruction pipeline

Answer 4

Fetch
Decode and register fetch
Execute
Memory access
Register write back

Question 5

Virtual memory principle

Answer 5

Processor request data from RAM. If data is in RAM, it will be fetched immediately. If the data is not in RAM, it will be requested from the disk. Data will be transferred from disk to RAM. the processor can now get them from RAM

Question 6

How does cache make cpu efficient?

Answer 6

It can quickly transfer information between the ram and cpu compared to how many cpu cycles it would take

Question 7

What is buffer overflow

Answer 7

If data entered is above the maximum, it is stored in memory and can be overflowed to store the out text

Question 8

Attacks against speculative execution

Answer 8

Mmu doesn’t check for permission to access memory. When it find the path to take, the cpu hits undo on the changes the wrong branch made. Doesn’t undo changes to cache

Question 9

Difference between cpu time sharing and multitasking

Answer 9

Time sharing is a fixed window of time for a process to execute on the pc and switches to another process when time sharing is over. Multitasking is switching the process at natural break points. Allows for prioritisation of processed.