Computer Architecture Flashcards
von neuman, harvard, memory types
name three (two) key aspects of Von-Neumann Architecture
- instructions to be executed and data are stored together in memory
- instructions are executed sequentially (one instruction at a time is fetched from memory)
- there is a single data bus
What is an “instruction” in the von-neumann architecture? How much data is transferred from memory to the CU when an “instruction” is fetched?
not sure ask prof.
I believe it is one line of assembly code.
This is why execution is normally sequential unless a line of assembly code says that execution should jump
what is von-neumann bottlenecking? Why does it happen?
There is only a single data bus connecting the memory, CPU (CU and ALU) and I/O. This means an instruction cannot be fetched at the same time data is being processed. The “bottleneck” is when the CPU can process instructions very quickly but the data bus is slower to get the instructions to the CPU than it could be able to handle
What type of data bus is used in Von-Neumann architecture?
application specific.
The architecture is simply a machine with the certain types of characteristics. This related to the data buses in that there is one, not the type.
what is a main disadvantage of Von-Neumann architecture?
von-neumann bottlenecking. (because there is only one data bus, and the CPU can only process one action and a time it can take multiple clock cycles for the CPU to carry out an instruction. )
summary:
- one data bus
- CPU single action
- multiple clock cycles
- bottlenecking
what are common applications of Von-Neumann architecture machines?
common computers.
avionics (hard to prove reliability with multiple cores)
what are some advantages of von neumann architecture?
The “simplifications” make is easier and cheaper for development
is the architecture still used today?
There are very few applications of the V-N architecture and Harvard architecture in their purest forms today.
describe the basic functioning of VN architecture
the cpu fetches instructions from the memory unit sequentially and processes them (moves data around or reads from input or writes to output)
how is memory organized `
unique addresses
what are the three parts of a CPU
CU, AU, registers
what is the purpose of registers
so if an instruction is to add the data does not have to be moved back into the main memory, two registers can simply be added by the ALU.
what are the roles of the ALU and CU in processing an instruction
The ALU actually performs the arithmetic operation and the CU controls the movement of data.
