Processor Components

These flashcards cover key concepts related to processor components and their functions as discussed in the provided lecture notes.

What is a microprocessor?

A digital device that processes input, stores values, and produces output according to on-board instructions.

What components are typically included in a processor?

Microprocessors include components like Arithmetic Logic Units (ALUs), Control Units, and registers.

What is the role of the Control Unit in a processor?

The Control Unit orchestrates the actions that occur in the datapath and is a finite state machine that instructs the datapath.

What is a datapath?

The datapath is where all data computations occur, often represented by the physical connections in a processor.

What are flip-flops?

Flip-flops are circuit components used for storage in digital circuits.

What does ALU stand for?

Arithmetic Logic Unit.

What operations can an ALU perform?

An ALU can perform both arithmetic operations (like addition and subtraction) and logical operations (like AND, OR, NOT).

What is the function of registers in a processor?

Registers store values temporarily for quick access during processing.

What is the significance of the instruction register (IR)?

The Instruction Register stores the currently executing instruction that has been fetched from memory.

What does the term 'fetch-execute cycle' refer to?

The cycle where the processor fetches the next instruction from memory, decodes it, and executes it.

How does the program counter (PC) work?

The PC keeps track of the address of the next instruction to be executed.

What is the purpose of the ALU's carry bit (Cin)?

The carry bit is used to handle overflow in addition and in the operations of incrementing.

What does the output signal 'Zero' from the ALU indicate?

It indicates whether the result of an operation is zero.

What is the purpose of multiplexers in datapaths?

Multiplexers select one of several input signals and forward the selected input to a single output line.

What role do tri-state buffers play in a processor?

Tri-state buffers allow multiple devices to share the same output line while controlling which device can send out data.

Define 'One-hot decoder'.

A one-hot decoder is used to select one of multiple outputs based on a binary input, activating only one output to 'high'.

How are instructions represented in MIPS architecture?

Instructions are represented as 32-bit binary strings where the first 6 bits are the opcode.

Explain the difference between R-type and I-type instructions.

R-type instructions operate on registers and include multiple register operands; I-type include an immediate value and a destination register.

What is Booth's algorithm used for?

Booth's algorithm is an efficient algorithm for multiplication that minimizes hardware requirements.

What does 'datapath control signals' mean?

Signals sent by the control unit to manage data flow and operations in the datapath during instruction execution.

What do the control signals ALUOp and RegWrite signify?

ALUOp specifies the operation for the ALU, and RegWrite indicates whether data should be written to a register.

How does the processor execute a load/store architecture?

The processor loads data from memory into registers before operations and stores results back into memory after computations.

What minimizes the size of an ALU design?

Optimizations that avoid duplicating logic help reduce the footprint of an ALU.

What is the function of a barrel shifter?

A barrel shifter allows for efficient left or right shifting and rotation of bits in a binary number.

What is the purpose of sign extension in I-type operations?

Sign extension is used to convert a smaller bit-sized value (like 16 bits) into a larger one (like 32 bits) while preserving its sign.

What are the different types of memory in a CPU?

Memory types include registers, cache, main memory (RAM), and secondary storage.

Explain the role of the data bus in a processor.

The data bus facilitates data transfer between the CPU and various memory units or input/output devices.

What is the purpose of the memory address decoder?

The memory address decoder activates the correct memory location based on the provided address.

What signaling indicates whether memory is being read or written?

The Read/Write Enable (R/W) signal determines whether the operation will be a read from or write to memory.

Define the term 'computer architecture'.

Computer architecture refers to the design and organization of a computer's components and the connections between them.

What is the function of the ALU signals V, N, C, and Z?

These signals indicate overflow (V), negative result (N), carry-out (C), and zero result (Z) conditions after ALU operations.

How are floating-point operations typically handled in processors?

Floating-point operations are handled by a dedicated floating-point unit (FPU) to manage precision and binary format.

What is a cache in relation to memory?

Cache is a smaller, faster type of volatile memory that stores copies of frequently accessed data for quicker retrieval.

How is an instruction decomposed for execution?

Instructions are broken down into the opcode and its operands in the instruction decoding phase.

What does R/W signal high signify?

When R/W is high, it signifies that the processor intends to read data from memory.

Explain the purpose of the fetch stage in the instruction cycle.

The fetch stage retrieves the next instruction from memory into the instruction register.

How is the branching feature implemented within CPUs?

Branching is implemented using the program counter and ALU to calculate new addresses based on conditions.

What does the IorD control signal indicate?

IorD determines whether an address is for an instruction or for data in memory retrieval.

What is an opcode?

An opcode is a portion of a machine language instruction that specifies the operation to be performed.

How does the concept of word alignment affect memory access?

Word alignment means that memory addresses are aligned to word boundaries, affecting access times and data retrieval efficiency.

What is the ultimate goal of a microprocessor?

The ultimate goal is to process instructions, manage input and output, and perform calculations effectively.

What technique can optimize multiplication in ALUs?

Using shift and add techniques or efficient algorithms like Booth's method can optimize multiplication.

Define the term 'load-store architecture'.

A load-store architecture restricts data processing to operations between registers, requiring loads and stores for memory access.

What are the main components of an arithmetic logic unit (ALU)?

The main components of ALS include the carry logic, arithmetic units for addition and subtraction, and logic gates for AND/OR operations.