Computer Architecture, Hardware domain of the CISSP Exam
Certified Information Systems Security Professional (CISSP) is an independent information security
certification granted by the International Information System Security Certification Consortium.
CISSP is a standardized, vendor-neutral certification program that provided structure and demonstrated
competence relevant to information security professionals.
Basic computer (system) architecture refers to the structure of a computer system and
comprises its hardware, firmware, and software.
The CompTIA A+ certification exam covers computer architecture in depth and is an excellent
way to prepare for this portion of the CISSP examination.
Hardware consists of the physical components in computer architecture. The main components
of the computer architecture include the CPU, memory, and bus.
The CPU (Central Processing Unit) or microprocessor is the electronic circuitry that
performs a computer's arithmetic, logic, and computing functions. As shown in the figure, the
main components of a CPU include
• Arithmetic Logic Unit (ALU): Performs numerical calculations and comparative
logic functions, such as ADD, SUBTRACT, DIVIDE, and MULTIPLY.
• Bus Interface Unit (BIU): Supervises data transfers over the bus system
between the CPU and I/O devices.
• Control Unit: Coordinates activities of the other CPU components during
• Decode Unit: Converts incoming instructions into individual CPU commands.
• Floating-Point Unit (FPU): Handles higher math operations for the ALU and
• Memory Management Unit (MMU): Handles addressing and cataloging data that's
stored in memory and translates logical addressing into physical addressing.
• Pre-Fetch Unit: Preloads instructions into CPU registers.
• Protection Test Unit (PTU): Monitors all CPU functions to ensure that they're
• Registers: Hold CPU data, addresses, and instructions temporarily, in special buffers.
The main components of a CPU.
The bus is a group of electronic conductors that interconnect the various components of the
computer, transmitting signals, addresses, and data between these components. Bus structures
are organized as follows:
• Data bus: Transmits data between the CPU, memory, and peripheral devices.
• Address bus: Transmits addresses of data and instructions between the CPU and memory.
• Control bus: Transmits control information (device status) between the CPU and other devices.
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