Processor Fundamentals Flashcards
What is the key realization behind the Von Neumann architecture?
Data and programs are indistinguishable and can be stored in the same memory.
How many processors does the Von Neumann architecture use?
A single processor.
What sequence of operations does the CPU follow in the Von Neumann architecture?
Fetch → Decode → Execute.
What is a register in a CPU?
A small, fast storage unit used for temporary data storage.
What are general-purpose registers used for?
Temporarily storing data values from memory or processed results.
What is the function of the Program Counter (PC)?
Holds the address of the next instruction to be fetched.
What does the Memory Data Register (MDR) do?
Holds the data value fetched from memory.
What does the Memory Address Register (MAR) store?
The address of the memory location to be accessed.
What is the role of the Accumulator (ACC)?
Stores values being processed by arithmetic & logic operations.
What does the Index Register (IX) do?
Stores a number used to modify an address value.
What is the function of the Current Instruction Register (CIR)?
Stores the fetched instruction for decoding & execution.
What does the Status Register hold?
Results of comparisons and intermediate or error results of arithmetic operations.
What is the Arithmetic and Logic Unit (ALU) responsible for?
Performing arithmetic and logical operations.
What does the Control Unit (CU) do?
Fetches, decodes, and synchronizes execution of instructions.
What is Immediate Access Store (IAS)?
Memory directly accessible by the CPU.
What is the purpose of the System Clock?
Synchronizes all CPU operations using pulses.
What is a bus in a computer system?
A set of parallel wires that transfer data between components.
What is the function of the Data Bus?
Transfers data between the processor, memory, and I/O devices (Bidirectional).
What does the Address Bus do?
Carries memory addresses from the processor to the MAR (Unidirectional).
What is the Control Bus used for?
Transmits control signals to avoid conflicts between components (Bidirectional).
How does Clock Speed affect CPU performance?
Higher clock speed means more instructions executed per second, improving performance.
Why is there a limit to increasing Clock Speed?
Higher speeds generate more heat, which can cause overheating
How does increasing Bus Width improve performance?
Allows more bits to be transferred simultaneously, increasing speed.
What is Cache Memory used for?
Stores frequently used instructions to reduce access time and improve performance.
How do multiple cores improve CPU performance?
Each core can process separate instructions simultaneously, improving efficiency.
What is the function of a Port in a CPU?
Provides a physical interface between the CPU and peripheral devices.
What type of devices can be connected via a USB port?
Both input and output devices.
What type of devices can be connected via an HDMI port?
Only output devices like monitors (transmits video & audio).
What is the main limitation of VGA ports?
They only transmit video, not audio.
What happens in the Fetch stage?
The CPU fetches the next instruction from memory.
What happens in the Decode stage?
The CPU identifies the opcode and operand of the instruction.
What happens in the Execute stage?
The instruction is executed using control signals.
What is an Interrupt?
A signal from a program or device requesting the CPU’s attention.
What happens when a high-priority interrupt occurs?
CPU saves current process, executes Interrupt Service Routine (ISR), then resumes execution.
Where does the CPU check for pending interrupts?
The Interrupt Register.
What is Assembly Language?
A low-level programming language using mnemonics for machine instructions.
What is Machine Code?
The binary representation of instructions understood by the processor.
How does an Assembler work?
Converts assembly language into machine code.
What is the difference between a One-pass and Two-pass Assembler?
A One-pass assembler translates code in one sweep but can’t handle forward references, while a Two-pass assembler builds a symbol table first and then generates the final machine code.
What is Direct Addressing?
The instruction directly specifies the memory address of the operand.
What is Indirect Addressing?
The instruction specifies an address that contains the actual address of the operand.
What is Indexed Addressing?
The address used is computed as a base address plus an offset from the Index Register.
What is Relative Addressing?
The next instruction’s address is calculated as an offset from the current address.
How does a Left Shift (LSL #n) affect a binary number?
Multiplies the number by 2^n by shifting bits left.
How does a Right Shift (LSR #n) affect a binary number?
Divides the number by 2^n by shifting bits right.
What is the difference between Logical Shift and Arithmetic Shift?
Logical Shift fills vacant bits with zeros, while Arithmetic Shift preserves the sign bit for signed numbers.
What is a Cyclic Shift?
A shift where the removed bit is added to the other end.
