Podcast
Questions and Answers
What action is performed to load data into register R2?
What action is performed to load data into register R2?
How many bits does the SEL OPR field in the control word contain?
How many bits does the SEL OPR field in the control word contain?
Which selection variable is used to load the contents of R2 into bus B?
Which selection variable is used to load the contents of R2 into bus B?
In the sequence of operations for the ALU, what does the operation 'R2out, Add, Zin' signify?
In the sequence of operations for the ALU, what does the operation 'R2out, Add, Zin' signify?
Signup and view all the answers
What is the purpose of using temporary registers during ALU operations?
What is the purpose of using temporary registers during ALU operations?
Signup and view all the answers
What determines which register is selected during a register transfer in a bus system?
What determines which register is selected during a register transfer in a bus system?
Signup and view all the answers
What configuration is used to construct the bus system for four registers?
What configuration is used to construct the bus system for four registers?
Signup and view all the answers
Which selection line combination corresponds to selecting register C?
Which selection line combination corresponds to selecting register C?
Signup and view all the answers
What is an advantage of using three-state gates in a bus system?
What is an advantage of using three-state gates in a bus system?
Signup and view all the answers
What happens when both selection lines S1 and S0 are set to low logic?
What happens when both selection lines S1 and S0 are set to low logic?
Signup and view all the answers
In a bus configuration using multiplexers, how many data inputs does each multiplexer have?
In a bus configuration using multiplexers, how many data inputs does each multiplexer have?
Signup and view all the answers
Which of the following correctly represents a basic characteristic of a three-state buffer gate?
Which of the following correctly represents a basic characteristic of a three-state buffer gate?
Signup and view all the answers
What type of circuit is mainly used for implementing a three-state bus system?
What type of circuit is mainly used for implementing a three-state bus system?
Signup and view all the answers
What is the primary function of the input unit in a computer system?
What is the primary function of the input unit in a computer system?
Signup and view all the answers
Which component of a computer system is often referred to as its 'brain'?
Which component of a computer system is often referred to as its 'brain'?
Signup and view all the answers
What critical function does the control unit perform within the CPU?
What critical function does the control unit perform within the CPU?
Signup and view all the answers
What is the purpose of the output unit in a computer system?
What is the purpose of the output unit in a computer system?
Signup and view all the answers
Which functional unit is responsible for performing arithmetic and logic operations in a computer?
Which functional unit is responsible for performing arithmetic and logic operations in a computer?
Signup and view all the answers
How does the control unit manage the flow of data within the CPU?
How does the control unit manage the flow of data within the CPU?
Signup and view all the answers
What role does the storage unit play in a computer system?
What role does the storage unit play in a computer system?
Signup and view all the answers
What is the main purpose of converting binary results to a human-readable format in an output unit?
What is the main purpose of converting binary results to a human-readable format in an output unit?
Signup and view all the answers
What is the main function of the Memory Address Register (MAR)?
What is the main function of the Memory Address Register (MAR)?
Signup and view all the answers
In the polling method of bus arbitration, how are devices prioritized?
In the polling method of bus arbitration, how are devices prioritized?
Signup and view all the answers
What is a characteristic of the Independent Request method?
What is a characteristic of the Independent Request method?
Signup and view all the answers
Which of the following describes centralized bus arbitration?
Which of the following describes centralized bus arbitration?
Signup and view all the answers
What is a disadvantage of the polling method?
What is a disadvantage of the polling method?
Signup and view all the answers
How many address lines are required when connecting eight masters in a polling method?
How many address lines are required when connecting eight masters in a polling method?
Signup and view all the answers
What role does the centralized bus arbiter play in the Independent Request method?
What role does the centralized bus arbiter play in the Independent Request method?
Signup and view all the answers
Which of the following is not a characteristic of registers in the CPU?
Which of the following is not a characteristic of registers in the CPU?
Signup and view all the answers
What does the Memory Data Register (MDR) contain?
What does the Memory Data Register (MDR) contain?
Signup and view all the answers
Which register holds the address of the instruction to be executed next?
Which register holds the address of the instruction to be executed next?
Signup and view all the answers
What is the first step in the process of reading data from memory when using registers?
What is the first step in the process of reading data from memory when using registers?
Signup and view all the answers
During a memory write operation, what must the MDR contain before issuing the write command?
During a memory write operation, what must the MDR contain before issuing the write command?
Signup and view all the answers
What role does the Input Output gating signal play in register transfer operations?
What role does the Input Output gating signal play in register transfer operations?
Signup and view all the answers
Which of the following actions is needed to transfer data from register R1 to register R2?
Which of the following actions is needed to transfer data from register R1 to register R2?
Signup and view all the answers
What is the function of the Instruction Buffer Register?
What is the function of the Instruction Buffer Register?
Signup and view all the answers
How is the Memory Fetch Cycle signaled to the system?
How is the Memory Fetch Cycle signaled to the system?
Signup and view all the answers
Study Notes
Functional Units of Digital System
- All computer systems perform five basic operations: input, output, storage, processing, and control
- These operations are carried out by five functional units: Input Unit, Output Unit, Storage Unit, Central Processing Unit (CPU), and Control Unit
Input Unit
- The Input Unit receives data and instructions from the outside world.
- It converts data from human-readable form to machine-readable form.
- This unit is responsible for transferring data from the outside world to the storage unit.
Output Unit
- The output unit delivers the results of computations and information to the outside world.
- It converts data from machine-readable form to human-readable form.
- It links the computer with the external environment.
Storage Unit
- The storage unit is responsible for storing data and instructions.
- It acts as a temporary or permanent storage space for the computer.
- Data is stored in the form of binary code.
Central Processing Unit (CPU)
- The CPU is the brain of the computer system.
- It carries out all major calculations, comparisons, and controls the operations of other units.
- The CPU consists of two main components: the Arithmetic and Logic Unit (ALU) and the Control Unit.
Arithmetic and Logic Unit (ALU)
- Performs arithmetic operations like addition, subtraction, multiplication, and division.
- Performs logic operations like AND, OR, NOT, and XOR.
- It is a combinational logic circuit, meaning it does not have any internal storage.
Control Unit
- Responsible for selecting, interpreting, and executing instructions.
- It controls the flow of data within the computer system
- It directs the operations of the entire system.
Buses
- Buses provide a path for data, instructions, and control signals to travel between different components of the system.
- Multiple registers can share a common bus, enabling efficient data transfer.
- Control signals are used to select the specific register that will transfer data through the bus.
Three-State Bus Buffers
- Three-state gates are used to construct bus systems, enabling multiple devices to share a common bus.
- These gates act like a switch, allowing data to pass through when enabled.
- When disabled, the gate creates a high-impedance state, cutting off the data flow.
Memory Transfer
- Memory Transfer refers to the process of transferring data between the CPU and memory.
- There are standard notations used to specify these memory transfers, including read (R), write (W), and memory fetch complete(MFC).
Bus Arbitration
- Bus arbitration is the process of resolving conflicts when multiple devices attempt to access the bus simultaneously.
- It ensures that only one device can access the bus at any given time.
- It utilizes a bus arbiter, which is a dedicated unit that manages the bus access.
Types of Bus Arbitration
- There are two main types of bus arbitration:
- Centralized Arbitration
- Distributed Arbitration
Centralized Arbitration
- Involves using a centralized bus arbiter that manages bus access for all devices.
- There are three common arbitration schemes:
- Daisy Chaining
- Polling Method
- Independent Request Method
Daisy Chaining
- A simple scheme where devices are connected in a chain.
- Priority is determined by the device’s position in the chain.
- The first device in the chain receives the highest priority.
Polling Method
- The bus controller assigns priorities dynamically to each device.
- This ensures that each device gets a chance to access the bus over time.
- The controller generates addresses for each master, and when the requesting master recognizes its address, it activates the busy line and begins using the bus.
Independent Request Method
- Each device has a dedicated bus request and bus grant lines, with assigned priorities.
- The central bus arbiter selects the highest priority request and asserts the corresponding bus grant signal.
Distributed Arbitration
- Each device can communicate directly with other devices to manage bus access.
- It does not rely on a central arbiter.
Registers
- Registers are essential for holding immediate data being used by the CPU.
- They are designed to store and transfer data quickly.
Types of Registers
- Memory Address Register (MAR): Stores the memory addresses of data and instructions.
- Memory Data Register (MDR): Holds the data to be written into or read from the addressed memory location.
- Accumulator Register: Stores the result of an operation.
- Data Register: Holds temporary data.
- Instruction Register (IR): Stores the current instruction being executed.
- Instruction Buffer Register: Holds temporary instructions.
- Program Counter (PC): Keeps track of the address of the next instruction to be executed.
- Index Register: Contains the address offset that needs to be added to a base address in the memory location.
Processor Organization
- The processor organization refers to the layout and interconnections between the components of the CPU and memory.
- A common organization involves the use of a common bus for data transfer between registers and memory.
- Data transfer operations between registers are achieved using register gating signals.
Memory Fetch Operation
- The CPU retrieves data or instructions from memory.
- The MAR stores the memory address of the desired data.
- A read command is issued to fetch the data into the MDR, and the MFC (Memory Fetch Complete signal) is received acknowledging the data transfer.
Storing a Word into Memory
- The CPU writes data into memory.
- The data is first loaded into the MDR.
- The address to be written to is stored in the MAR.
- A write command is issued, and the MFC signal indicates the completion of the operation.
Register Transfer Operation
- Data transfer between registers connected to the CPU bus.
- Input and output gates control the transfer of data between registers.
- This ensures a coordinated flow of information between the CPU’s internal registers.
General Register Organization
- Each CPU has multiple general-purpose registers, providing flexibility in storing and manipulating data.
- By providing multiple registers, the CPU can efficiently process multiple operands.
Control Word
- A control word is a set of bits used to control the operations of the CPU.
- Different bits within the control word are dedicated to selecting the specific operation, registers, or data paths needed for the current operation.
- It specifies the instruction and data to be processed, and the destination of the result.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the five fundamental functional units of digital systems: Input Unit, Output Unit, Storage Unit, CPU, and Control Unit. This quiz covers their roles and operations in handling data and instructions in computer systems. Gain a deeper understanding of how these components interact to achieve computing tasks.
