System architecture Flashcards
what is an embedded system
a small dedicated system that performs specific tasks related to their function within a larger system.
what are the disadvantages of an embedded system
very narrow skill set
three advantages of an embedded system
easier to design, cheaper to produce and more efficient at its task than a general computer
what is the overall purpose of the CPU
to process data and instructions
what three factors effect CPU speed
clock speed, number of cores and cache size
what are the three components that make up the CPU
Control unit, Arithmetic logic unit and cache
what is the function of the control unit
To manage the fetch decode execute cycle and oversee the flow of data in and out of the CPU
what three things are typically closely linked to the CPU
main memory, input and output devices
what is the function of the ALU
It completes all the arithmetic calculations, and performs logic operations
what is the function of the cache
High speed, volatile memory close to the CPU that holds regularly used data
what is the function of the program counter
Holds the address of the next instruction for each cycle
what is the purpose of the MAR
hold the address of the instruction the CPU is about to use
what is the purpose of the MDR
To hold the actual data, ready to be written into memory or already fetched from memory
what is the purpose of the accumalator
To store the results of calculations made by the ALU
what happens in the fetch part of the fetch-decode-execute cycle
“Memory address is copied from PC to MAR, and then the instruction goes to the MDR. PC is then increased
to point to the address of the next instruction of the cycle
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