system architecture Flashcards
what are embedded systems
they are systems that are embedded into other devices.
examples of embedded system
dishwashers, microwave, and TVs
why are embedded systems good
they only have one task so they are optimized for it
what is the fetch-decode-execute cycle
It is all a CPU does, carrying out instructions. it does this in three stages, fetch, decode, execute. it does this cycle billions of times a second.
Stage one - Fetch
the CPU fetches data and instructions from (RAM) then stores them in the registers. the CPU request data and sends it to the RAM via the address bus. the data bus sends data from the RAM to the CPU
Stage Two - Decode
looks at instructions to understand what the user wants. then prepares for the next stage
Stage Three - Execute
preforms these instructions. once this cycle has completed another one begins
What makes up the CPU
it is made from three main parts:
the Control unit
Cache
Arithmetic and logic unit
what is the control unit
It manages and monitors hardware on computers. and makes sure it goes to the right place.
it manages the input and output and makes sure everything is right.
it manages the fetch-decode-execute cycle.
what is the Cache
stores data that is about to be processed. it takes instructions from the RAM and stores them in the cache to make sure it always has instructions to process.
what is the arithmetic & logic unit
where the CPU carries out math and logic data. logic controls things like true or false
