WEEK 2- CPU Flashcards
What is a central processing unit (CPU)?
Fundamental component of every computer system, which executes all the tasks required by a computer system.
Why is a central processing unit ‘central’?
All actions of the computer system are initiated by the CPU.
What is the general role of the computer’s central processing unit?
Every task carried out by a computer is done by the CPU performing a sequence
of ‘simple’ machine language instructions.
What language is actually ‘understood’ by a computer’s CPU?
Different CPUs may have different machine languages.
A program written in the machine language of one type of CPU will probably not
work on a system with a different type of CPU.
What are the main internal hardware components of a typical CPU?
A Control Unit
A arithmietic/logic unit (ALU)
What is the role of the instruction register of a CPU?
This register stores the binary word that represents the single machine language
instruction that the CPU is currently executing.
What is the role of the program counter register of a CPU?
This register stores the binary word that represents the ADDRESS in main
memory of the current or next machine language instruction in the program being
executed
What is the role of the status register(s) of a CPU?
This register stores information about the status of various devices on the
systems and about the outcomes of various operations carried out by the CPU.
What is the role of the general purpose registers of a CPU?
Store binary words that represent data values, and can manipulated according to machine instructions obeyed by CPU.
What is a CPU’s machine cycle?
During the machine cycle the CPU gets machine instructions from the system’s
main memory and carries out the instructions.
What are the stages in a CPU’s machine cycle?
Fetch- (read the program counter and put the instruction in the instruction register)
Interpret- (read from the instruction register)
Execute- (do the task in the instruction register)
Increment- (modify the program counter)
What is an ALU?
arithmetic/logic unit- Performs arithmetic and logical manipulation of the contents of binary words.
What controls the speed of the machine cycle?
Electronic timing device called a ‘clock’ which produces a constant frequency of pulses.
What is a clock speed of
a) . 1 Megahertz (1MHz)
b) . 1 Gigahertz (1GHz)
a) . 1,000,000 beats per second
b) . 1,000,000,000 beats per second
