Fetch Execute Cycle Flashcards
General purpose
register
a register not assigned a specific role by the processor designer. Programmers may use general-purpose registers.
Dedicated
register
a register assigned a specific role by the processor designer. Programmers may use some but not all dedicated registers
Program Counter
Stores the address of the next instruction to be executed
Memory Address Register
Stores the data or instruction being transferred to and from the immediate access store
Current Instruction Register
Register that is part of a CPU’s control unit and stores
the instruction currently being executed or decoded.
Accumulator
Stores results of arithmetic and logic operations
Bus
Set of parallel wires connecting independent components of a computer system
Address bus
Carries an identification (i.e. physical address) about where the data are being sent (uni-directional)
Data bus
Carries the actual data or instruction to be processed between the CPU and the other internal components such as main memory and I/O ports (bidirectional)
Control bus
Carries commands from the control unit and returns status signals from the devices such as timing signals,
acknowledgement signals and read/write signals (bidirectional)
ALU
Arithmetic Logic Unit. A digital circuit (component) used to process and manipulate data / performs calculations / logical operations.
Control Unit
It is a component of a CPU. Control unit directs the operations of the processor. It tells the computer’s memory, arithmetic/logic unit and input and output devices how to respond to a program’s instructions.
Decoder
The decoder is the circuit inside the control unit that decodes an op-code from the CIR.
Memory Data/Buffer Register
A two-way register that holds data fetched from memory ( and ready for the CPU to process) or data waiting to be stored in memory)
Fetch execute cycle
PC -next address
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