What are the 3 main components in the von Neumann architecture?
CPU, Memory, I/O modules.
What’s the key idea of the stored-program concept?
Instructions and data are stored together in memory.
What are the 4 basic computer functions?
Data processing, Data storage, Data movement, Control.
What are the 3 stages of the instruction cycle?
Fetch → Decode → Execute (sometimes Store as part of Execute).
During fetch, which register holds the next instruction’s address?
Program Counter (PC).
Which unit decodes the instruction’s opcode?
Control Unit (CU).
Which unit performs arithmetic and logic operations?
Arithmetic Logic Unit (ALU).
What is an interrupt?
A signal that temporarily stops the CPU so it can handle an urgent event.
List 4 common types of interrupts.
Program, Timer, I/O, Hardware failure.
What is an Interrupt Service Routine (ISR)?
Special code that handles an interrupt, then returns control to the program.
What happens when an interrupt occurs?
CPU finishes current instruction → saves state → jumps to ISR → restores state → resumes program.
What is the difference between sequential and nested interrupt handling?
Sequential = one ISR at a time, no new interrupts allowed. Nested = higher-priority interrupts can preempt lower ones.
What is a bus in computer architecture?
A set of communication lines connecting CPU, memory, and I/O.
What does the data bus carry?
Actual data (instructions or operands).
What does the address bus carry?
The address of the memory location or I/O port.
What does the control bus carry?
Control signals (read/write, interrupt requests, clock).
If a system has a 32-bit address bus, how much memory can it address?
2³² = 4,294,967,296 bytes = 4 GB.
We just put as 2 to the power n aka the bits
What’s the difference between synchronous and asynchronous bus timing?
Synchronous = uses common clock, faster but rigid. Asynchronous = handshaking signals, slower but flexible.
What is bus arbitration?
The process of deciding which device gets control of the bus when multiple request it.
What are the 2 methods of bus arbitration?
Centralized (bus controller decides), Distributed (devices negotiate).
What are 3 interconnection structures?
Single bus, Multiple bus, Crossbar/Point-to-point.
