Unit 1 Long Answers QB Solution PDF

+-----------------------+-----------------------+-----------------------+ | **S.No.** | **Question** | **COURSE OUTCOMES** | +=======================+=======================+=======================+ | **a)** | **Explain | **CO1** | |...

+-----------------------+-----------------------+-----------------------+ | **S.No.** | **Question** | **COURSE OUTCOMES** | +=======================+=======================+=======================+ | **a)** | **Explain | **CO1** | | | Accumulator?** | | +-----------------------+-----------------------+-----------------------+ | **Ans.** | **An accumulator is a | | | | register within the | | | | Central Processing | | | | Unit (CPU) that is | | | | primarily used to | | | | store intermediate | | | | results during | | | | arithmetic and | | | | logical computations | | | | performed by the | | | | Arithmetic Logic Unit | | | | (ALU). It plays a | | | | crucial role in | | | | simplifying the | | | | execution of | | | | instructions in a | | | | processor.** | | | | | | | | **Role of an | | | | Accumulator** | | | | | | | | 1. Intermediate | | | | Result Storage | | | | | | | | - When the ALU | | | | performs an | | | | operation, | | | | the | | | | intermediate | | | | result is | | | | stored in the | | | | accumulator. | | | | For example, | | | | during | | | | addition, the | | | | sum of two | | | | numbers is | | | | placed in the | | | | accumulator, | | | | ready for | | | | further | | | | operations. | | | | | | | | 2. Facilitates | | | | Sequential | | | | Computation | | | | | | | | - By storing | | | | results of | | | | one | | | | operation, | | | | the | | | | accumulator | | | | allows for | | | | the next | | | | operation to | | | | build upon it | | | | without | | | | requiring | | | | frequent | | | | memory | | | | access. | | | | | | | | 3. Enhances | | | | Efficiency | | | | | | | | - It minimizes | | | | the need to | | | | read/write | | | | data back to | | | | main memory | | | | during | | | | computations, | | | | which speeds | | | | up processing | | | | and reduces | | | | the overhead. | | | | | | | | **Structure of the | | | | Accumulator** | | | | | | | | The accumulator is | | | | usually a | | | | **special-purpose | | | | register** in the | | | | CPU. It is directly | | | | connected to the ALU, | | | | allowing it to | | | | interact with other | | | | components of the | | | | CPU. Here\'s a | | | | conceptual view of | | | | the accumulator\'s | | | | role: | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-- | | | | + | | | | | | | | \| Registers \| | | | | | | | | +\-\-\-\-\-\-\--+\-\- | | | | \-\-\-\-\-\-\-\-\--+ | | | | | | | | \| | | | | | | | | v | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-- | | | | + | | | | | | | | \| ALU \| | | | | | | | | +\-\-\-\-\-\-\--+\-\- | | | | \-\-\-\-\-\-\-\-\--+ | | | | | | | | \| | | | | | | | | v | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\--+ | | | | | | | | \| Accumulator \| | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\--+ | | | | | | | | **How an Accumulator | | | | Works** | | | | | | | | 1. The **ALU** | | | | receives operands | | | | (inputs) either | | | | from the | | | | accumulator | | | | itself or other | | | | registers. | | | | | | | | 2. It performs the | | | | required | | | | computation | | | | (e.g., addition, | | | | subtraction, | | | | logical AND). | | | | | | | | 3. The result of the | | | | computation is | | | | stored back into | | | | the accumulator. | | | | | | | | This process is | | | | repeated for | | | | subsequent | | | | operations, using the | | | | value in the | | | | accumulator as one of | | | | the operands. | | | | | | | | **Example: Summing | | | | Numbers** | | | | | | | | Consider the addition | | | | of three numbers (A, | | | | B, C) using the | | | | accumulator. | | | | | | | | **Step-by-Step | | | | Process** | | | | | | | | 1. Load A into the | | | | accumulator. | | | | | | | | 2. Add B to the | | | | value in the | | | | accumulator; the | | | | result is stored | | | | in the | | | | accumulator. | | | | | | | | 3. Add C to the | | | | value in the | | | | accumulator; the | | | | final result | | | | remains in the | | | | accumulator. | | | | | | | | **Instruction | | | | Example** | | | | | | | | In a hypothetical | | | | instruction set: | | | | | | | | **Instruction** * | | | | *Description** | | | | ----------------- - | | | | --------------------- | | | | ----------------- | | | | LOAD A L | | | | oad value of A into t | | | | he accumulator. | | | | ADD B A | | | | dd B to the accumulat | | | | or. | | | | ADD C A | | | | dd C to the accumulat | | | | or. | | | | | | | | **Execution** | | | | | | | | - After LOAD A, the | | | | accumulator | | | | contains the | | | | value of A. | | | | | | | | - After ADD B, the | | | | accumulator | | | | contains A+BA + | | | | BA+B. | | | | | | | | - After ADD C, the | | | | accumulator | | | | contains A+B+CA + | | | | B + CA+B+C. | | | | | | | | **Advantages of Using | | | | an Accumulator** | | | | | | | | 1. **Reduced Memory | | | | Access** | | | | | | | | - Operations | | | | are performed | | | | using the | | | | accumulator, | | | | reducing the | | | | need to | | | | access main | | | | memory | | | | repeatedly. | | | | | | | | 2. **Faster | | | | Computations** | | | | | | | | - Since the | | | | accumulator | | | | is within the | | | | CPU, data | | | | transfer | | | | between the | | | | ALU and the | | | | accumulator | | | | is much | | | | faster than | | | | accessing | | | | memory. | | | | | | | | 3. **Simplified | | | | Instruction Set** | | | | | | | | - Many | | | | processors | | | | use | | | | accumulator-b | | | | ased | | | | architectures | | | | , | | | | which | | | | simplify | | | | instruction | | | | design and | | | | execution. | | | | | | | | **Accumulator in a | | | | Basic Computer | | | | System** | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | | | | | | | \| Control Unit \| | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | | | | | | | \| | | | | | | | | v | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | | | | | | | \| Arithmetic Logic | | | | Unit \| | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | | | | | | | \| | | | | | | | | v | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | | | | | | | \| Accumulator \| | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | | | | | | | \| | | | | | | | | v | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | | | | | | | \| Data Bus / Main | | | | Memory \| | | | | | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\--+ | | +-----------------------+-----------------------+-----------------------+ | **b)** | **Draw a space | **CO1** | | | diagram for a | | | | five-segment pipeline | | | | showing the time is | | | | take to process 10 | | | | tasks?** | | +-----------------------+-----------------------+-----------------------+ | **Ans.** | **A pipeline in | | | | computer architecture | | | | is a technique that | | | | allows overlapping | | | | execution of multiple | | | | instructions to | | | | improve system | | | | throughput. It is | | | | analogous to an | | | | assembly line in a | | | | factory where | | | | different stages of | | | | instruction | | | | processing are | | | | executed | | | | simultaneously.** | | | | | | | | **Five-Segment | | | | Pipeline Stages** | | | | | | | | **A five-segment | | | | pipeline typically | | | | involves the | | | | following stages:** | | | | | | | | 1. **Instruction | | | | Fetch (IF):** | | | | | | | | - **Fetches the | | | | instruction | | | | from | | | | memory.** | | | | | | | | 2. **Instruction | | | | Decode (ID):** | | | | | | | | - **Decodes the | | | | fetched | | | | instruction | | | | and prepares | | | | for | | | | execution.** | | | | | | | | 3. **Execution | | | | (EX):** | | | | | | | | - **Executes | | | | the | | | | instruction | | | | (e.g., | | | | arithmetic/lo | | | | gic | | | | operation).** | | | | | | | | 4. **Memory Access | | | | (MEM):** | | | | | | | | - **Accesses | | | | memory if | | | | needed (e.g., | | | | for | | | | Load/Store | | | | operations).* | | | | * | | | | | | | | 5. **Write Back | | | | (WB):** | | | | | | | | - **Writes the | | | | result back | | | | to a register | | | | or memory.** | | | | | | | | **Each stage | | | | processes one part of | | | | an instruction in | | | | parallel with other | | | | stages.** | | | | | | | | **Pipeline | | | | Operation** | | | | | | | | **In a pipeline, | | | | instruction execution | | | | is divided into | | | | steps. Each | | | | instruction passes | | | | through all five | | | | stages sequentially, | | | | but multiple | | | | instructions can be | | | | in different stages | | | | at the same time.** | | | | | | | | 1. **Latency:** | | | | | | | | - **The time | | | | required for | | | | one | | | | instruction | | | | to pass | | | | through all | | | | pipeline | | | | stages.** | | | | | | | | 2. **Throughput:** | | | | | | | | - **The number | | | | of | | | | instructions | | | | completed per | | | | unit time, | | | | which | | | | increases | | | | with | | | | pipelining.** | | | | | | | | **Space Diagram** | | | | | | | | **Below is a space | | | | diagram showing the | | | | time taken to process | | | | 10 tasks | | | | (instructions) in a | | | | five-segment | | | | pipeline. Each column | | | | represents a clock | | | | cycle, and each row | | | | corresponds to a | | | | pipeline stage.** | | | | | | | | **Space-Time Diagram | | | | for 10 Instructions** | | | | | | | | **Clock Cycle \--\> 1 | | | | 2 3 4 5 6 7 8 9 10 11 | | | | 12 13 14** | | | | | | | | **\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\-\-\-\-\- | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\-\-\-\-\- | | | | -** | | | | | | | | **Instruction 1: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 2: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 3: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 4: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 5: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 6: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 7: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 8: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 9: IF | | | | ID EX MEM WB** | | | | | | | | **Instruction 10: IF | | | | ID EX MEM WB** | | | | | | | | **Explanation of the | | | | Diagram** | | | | | | | | 1. **Clock Cycle | | | | 1-5:** | | | | | | | | - **Instruction | | | | 1 passes | | | | through all | | | | five pipeline | | | | stages | | | | sequentially. | | | | ** | | | | | | | | 2. **Clock Cycle | | | | 6:** | | | | | | | | - **Instruction | | | | 1 completes | | | | the Write | | | | Back (WB) | | | | stage.** | | | | | | | | - **Instruction | | | | 2 finishes | | | | Execution | | | | (EX).** | | | | | | | | - **Instruction | | | | 3 starts | | | | Instruction | | | | Decode | | | | (ID).** | | | | | | | | - **Instruction | | | | 4 starts | | | | Instruction | | | | Fetch (IF).** | | | | | | | | 3. **Overlap:** | | | | | | | | - **Multiple | | | | instructions | | | | are in | | | | different | | | | stages | | | | simultaneousl | | | | y | | | | after the | | | | pipeline is | | | | filled.** | | | | | | | | 4. **Completion:** | | | | | | | | - **After 14 | | | | clock cycles, | | | | all 10 | | | | instructions | | | | are | | | | executed.** | | | | | | | | **Pipeline Timing | | | | Analysis** | | | | | | | | 1. **Without | | | | Pipelining:** | | | | | | | | - **Each | | | | instruction | | | | requires 5 | | | | clock | | | | cycles.** | | | | | | | | - **For 10 | | | | instructions, | | | | 10×5=5010 | | | | \\times 5 = | | | | 5010×5=50 | | | | clock cycles | | | | are needed.** | | | | | | | | 2. **With | | | | Pipelining:** | | | | | | | | - **The first | | | | instruction | | | | takes 5 clock | | | | cycles to | | | | complete.** | | | | | | | | - **Each | | | | subsequent | | | | instruction | | | | is completed | | | | in one | | | | additional | | | | cycle.** | | | | | | | | - **For 10 | | | | instructions: | | | | Time Required | | | | =5+(10−1)=14 clock cy | | | | cles.\\text{Time | | | | Required} = | | | | 5 + (10 - 1) | | | | = 14 \\text{ | | | | clock | | | | cycles.}Time  | | | | Required=5+(10−1)=14  | | | | clock cycles.** | | | | | | | | **Advantages of | | | | Pipelining** | | | | | | | | 1. **Improved | | | | Throughput:** | | | | | | | | - **Increases | | | | the number of | | | | instructions | | | | executed per | | | | unit time.** | | | | | | | | 2. **Parallelism:** | | | | | | | | - **Multiple | | | | instructions | | | | are processed | | | | simultaneousl | | | | y.** | | | | | | | | 3. **Efficiency:** | | | | | | | | - **Maximizes | | | | CPU | | | | utilization | | | | by keeping | | | | all parts of | | | | the processor | | | | active.** | | +-----------------------+-----------------------+-----------------------+ | **c)** | **Differentiate | **CO2** | | | between computer | | | | organization and | | | | computer | | | | architecture.** | | +-----------------------+-----------------------+-----------------------+ | **Ans.** | **Difference Between | | | | Computer Organization | | | | and Computer | | | | Architecture** | | | | | | | | **Computer systems | | | | are complex entities, | | | | and understanding | | | | their design requires | | | | distinguishing | | | | between Computer | | | | Organization and | | | | Computer | | | | Architecture. These | | | | concepts, though | | | | related, focus on | | | | different aspects of | | | | the system.** | | | | | | | | **Computer | | | | Organization** | | | | | | | | **Computer | | | | Organization refers | | | | to the physical | | | | aspects of a computer | | | | system, focusing on | | | | how the hardware | | | | components interact | | | | and are implemented. | | | | It deals with | | | | elements like memory | | | | size, processor | | | | design, data paths, | | | | and input/output | | | | devices. The goal is | | | | to optimize | | | | performance by | | | | addressing hardware | | | | efficiency.** | | | | | | | | **Computer | | | | Architecture** | | | | | | | | **Computer | | | | Architecture, on the | | | | other hand, is | | | | concerned with the | | | | logical design of a | | | | system, focusing on | | | | its functionality and | | | | programming model. It | | | | defines how | | | | instructions are | | | | executed, data is | | | | processed, and memory | | | | is managed.** | | | | | | | | **Key Differences** | | | | | | | | **Aspect** ** | | | | Computer Organization | | | | ** | | | | **Computer Archite | | | | cture** | | | | ---------------- -- | | | | --------------------- | | | | --------------------- | | | | -- ------------------ | | | | --------------------- | | | | ----------- | | | | **Definition** ** | | | | Implementation detail | | | | s of hardware.** | | | | **Design and funct | | | | ionality of the syste | | | | m.** | | | | **Focus** ** | | | | Physical components a | | | | nd their operation.** | | | | **Logical structur | | | | e and programming int | | | | erface.** | | | | **Examples** ** | | | | Data paths, memory te | | | | chnology.** | | | | **Instruction set | | | | design, addressing mo | | | | des.** | | | | | | | | **Example: Consider a | | | | computer with a | | | | 64-bit processor.** | | | | | | | | - **Architecture: | | | | Focuses on what a | | | | 64-bit processor | | | | means for | | | | software (e.g., | | | | larger data | | | | types).** | | | | | | | | - **Organization: | | | | Focuses on the | | | | actual hardware | | | | implementation of | | | | 64-bit processing | | | | (e.g., transistor | | | | design).** | | +-----------------------+-----------------------+-----------------------+ | **d)** | **What is a control | **CO2** | | | Bus, explain in | | | | details?** | | +-----------------------+-----------------------+-----------------------+ | **Ans.** | **The control bus is | | | | an essential | | | | communication pathway | | | | in a computer system | | | | that is responsible | | | | for managing and | | | | coordinating the | | | | operations between | | | | the CPU (Central | | | | Processing Unit) and | | | | other components such | | | | as memory and I/O | | | | (Input/Output) | | | | devices. The control | | | | bus plays a pivotal | | | | role in ensuring that | | | | the various | | | | components work | | | | together seamlessly, | | | | as it carries signals | | | | that control the | | | | behavior and timing | | | | of these | | | | components.** | | | | | | | | **Role of the Control | | | | Bus** | | | | | | | | **In a computer | | | | system, numerous | | | | operations occur | | | | simultaneously, such | | | | as fetching data from | | | | memory, writing data | | | | to memory, and | | | | interacting with I/O | | | | devices. To ensure | | | | these operations | | | | occur without | | | | conflicts or errors, | | | | the CPU uses the | | | | control bus to send | | | | signals that:** | | | | | | | | 1. **Synchronize | | | | tasks.** | | | | | | | | 2. **Specify the | | | | type of operation | | | | (read/write).** | | | | | | | | 3. **Handle special | | | | requests like | | | | interrupts from | | | | peripherals.** | | | | | | | | **Functions of the | | | | Control Bus** | | | | | | | | **The control bus | | | | carries various | | | | signals that enable | | | | the CPU to | | | | communicate and | | | | manage other system | | | | components | | | | effectively. Its | | | | primary functions | | | | include:** | | | | | | | | **1. | | | | Synchronization** | | | | | | | | - **Every component | | | | in a computer | | | | system operates | | | | at a certain | | | | speed and | | | | requires precise | | | | timing to avoid | | | | errors or | | | | conflicts.** | | | | | | | | - **The control bus | | | | carries clock | | | | signals that | | | | ensure all | | | | components | | | | operate in sync | | | | with the CPU\'s | | | | clock. For | | | | example, during | | | | data transfer, | | | | the memory must | | | | place data on the | | | | data bus at the | | | | exact moment the | | | | CPU expects to | | | | receive it.** | | | | | | | | **2. Operation | | | | Control** | | | | | | | | - **The CPU uses | | | | the control bus | | | | to indicate the | | | | type of operation | | | | it wants to | | | | perform, such as | | | | reading data from | | | | memory, writing | | | | data to memory, | | | | or communicating | | | | with an I/O | | | | device.** | | | | | | | | - **Read/Write | | | | Signals are part | | | | of the control | | | | bus. For | | | | example:** | | | | | | | | - **A Read | | | | Signal tells | | | | memory to | | | | provide | | | | data.** | | | | | | | | - **A Write | | | | Signal | | | | instructs | | | | memory to | | | | store data.** | | | | | | | | **3. Interrupt | | | | Handling** | | | | | | | | - **Peripheral | | | | devices like | | | | keyboards, | | | | printers, or | | | | network adapters | | | | often need to | | | | notify the CPU of | | | | events that | | | | require immediate | | | | attention.** | | | | | | | | - **The control bus | | | | carries interrupt | | | | signals that | | | | alert the CPU. | | | | For instance, | | | | when a printer | | | | finishes a job, | | | | it sends an | | | | interrupt request | | | | via the control | | | | bus, prompting | | | | the CPU to handle | | | | the next task.** | | | | | | | | **Key Signals on the | | | | Control Bus** | | | | | | | | **The control bus | | | | transmits several | | | | important signals to | | | | coordinate system | | | | operations:** | | | | | | | | 1. **Read/Write | | | | Signal** | | | | | | | | - **Specifies | | | | whether the | | | | operation is | | | | a Read (data | | | | retrieval) or | | | | Write (data | | | | storage).** | | | | | | | | - **For | | | | example:** | | | | | | | | - **A Read | | | | signal | | | | tells the | | | | memory to | | | | place | | | | requested | | | | data onto | | | | the data | | | | bus.** | | | | | | | | - **A Write | | | | signal | | | | instructs | | | | the | | | | memory to | | | | accept | | | | data from | | | | the data | | | | bus.** | | | | | | | | 2. **Clock Signal** | | | | | | | | - **Provides | | | | synchronizati | | | | on | | | | by generating | | | | regular | | | | pulses, | | | | ensuring all | | | | components | | | | operate in | | | | step with the | | | | CPU\'s | | | | timing.** | | | | | | | | 3. **Interrupt | | | | Requests** | | | | | | | | - **Devices use | | | | this signal | | | | to notify the | | | | CPU about | | | | high-priority | | | | events that | | | | require | | | | immediate | | | | action.** | | | | | | | | - **For | | | | instance, a | | | | network card | | | | might send an | | | | interrupt | | | | when new data | | | | arrives.** | | | | | | | | 4. **Reset Signal** | | | | | | | | - **Used to | | | | reset the | | | | system, | | | | clearing | | | | registers and | | | | restarting | | | | operations in | | | | a known | | | | state.** | | | | | | | | **Diagram of the | | | | Control Bus** | | | | | | | | **The relationship | | | | between the CPU, | | | | control bus, and | | | | other components can | | | | be visualized as | | | | follows:** | | | | | | | | **+\-\-\-\-\-\-\-\--+ | | | | Control Bus | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \--+ | | | | Control Bus | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \--+** | | | | | | | | **\| CPU \| | | | | \-\-\-\-\-\-\-\-\-\-\ | | | | -\-\-\-\-\-\-\-\--\> | | | | \| Memory \| | | | | \ | | | | \| I/O \|** | | | | | | | | **+\-\-\-\-\-\-\-\--+ | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \--+ | | | | +\-\-\-\-\-\-\-\-\-\- | | | | \--+** | | | | | | | | **In this diagram:** | | | | | | | | 1. **The CPU sends | | | | control signals | | | | via the control | | | | bus to coordinate | | | | tasks with memory | | | | and I/O | | | | devices.** | | | | | | | | 2. **Memory or I/O | | | | devices respond | | | | based on these | | | | signals, ensuring | | | | operations like | | | | data transfer | | | | occur without | | | | conflicts.** | | | | | | | | **Example of Control | | | | Bus Usage** | | | | | | | | **Suppose the CPU | | | | needs to read data | | | | from memory:** | | | | | | | | 1. **The CPU sends | | | | the address of | | | | the data to the | | | | memory using the | | | | address bus.** | | | | | | | | 2. **A Read signal | | | | is sent via the | | | | control bus to | | | | indicate the | | | | operation type.** | | | | | | | | 3. **The memory | | | | places the | | | | requested data | | | | onto the data | | | | bus, which the | | | | CPU retrieves.** | | | | | | | | 4. **If the CPU | | | | receives an | | | | interrupt signal | | | | during this | | | | process, it | | | | pauses its | | | | current task to | | | | handle the | | | | interrupt.** | | | | | | | | **Importance of the | | | | Control Bus** | | | | | | | | **The control bus is | | | | vital for the | | | | following reasons:** | | | | | | | | 1. **Coordination: | | | | Ensures that all | | | | components in the | | | | system work | | | | together | | | | seamlessly.** | | | | | | | | 2. **Error | | | | Prevention: | | | | Reduces the | | | | chances of | | | | conflicts during | | | | data transfer.** | | | | | | | | 3. **Efficient | | | | Interrupt | | | | Handling: Allows | | | | the CPU to manage | | | | peripheral | | | | requests | | | | effectively, | | | | ensuring smooth | | | | operation.** | | | | | | | | **Without a control | | | | bus, components like | | | | memory and I/O | | | | devices would not | | | | know how to respond | | | | to CPU instructions, | | | | leading to system | | | | malfunction.** | | | | | | | | **Extended Example: | | | | Real-Life Scenario** | | | | | | | | **Consider a scenario | | | | where a user presses | | | | a key on a keyboard, | | | | which is connected to | | | | the computer via an | | | | I/O port:** | | | | | | | | 1. **The keyboard | | | | generates an | | | | interrupt signal | | | | indicating a key | | | | press.** | | | | | | | | 2. **The interrupt | | | | signal travels to | | | | the CPU via the | | | | control bus.** | | | | | | | | 3. **The CPU | | | | processes the | | | | interrupt, | | | | identifies the | | | | key pressed, and | | | | stores the | | | | corresponding | | | | data in memory.** | | | | | | | | 4. **The CPU sends a | | | | Write signal via | | | | the control bus, | | | | instructing | | | | memory to store | | | | the data.** | | | | | | | | **This sequence | | | | demonstrates how the | | | | control bus enables | | | | smooth interaction | | | | between components.** | | +-----------------------+-----------------------+-----------------------+ | **e)** | **What is an address | **CO3** | | | Bus, explain in | | | | details?** | | +-----------------------+-----------------------+-----------------------+ | **Ans.** | **Address Bus** | | | | | | | | **The address bus is | | | | a critical component | | | | of a computer's | | | | communication system, | | | | enabling the CPU to | | | | identify specific | | | | memory locations or | | | | I/O devices. Its | | | | primary purpose is to | | | | carry addresses, | | | | which serve as unique | | | | identifiers for data | | | | or instructions in | | | | memory.** | | | | | | | | **Characteristics of | | | | the Address Bus** | | | | | | | | 1. **Unidirectional | | | | Nature:** | | | | | | | | - **The address | | | | bus is | | | | unidirectiona | | | | l, | | | | meaning that | | | | it only | | | | carries | | | | signals in | | | | one | | | | direction---f | | | | rom | | | | the CPU to | | | | the memory or | | | | I/O | | | | devices.** | | | | | | | | - **This is | | | | because the | | | | CPU sends the | | | | address of | | | | the location | | | | it wants to | | | | access, and | | | | memory or | | | | devices | | | | respond | | | | accordingly.* | | | | * | | | | | | | | 2. **Width | | | | Determines | | | | Addressable | | | | Memory:** | | | | | | | | - **The number | | | | of lines (or | | | | bits) in the | | | | address bus | | | | determines | | | | the range of | | | | addresses the | | | | CPU can | | | | access.** | | | | | | | | - **Example:** | | | | | | | | - **A | | | | 16-bit | | | | address | | | | bus can | | | | address | | | | 216=65,53 | | | | 62\^{16} | | | | = | | | | 65,536216 | | | | =65,536 | | | | (64 KB) | | | | unique | | | | memory | | | | locations | | | |.** | | | | | | | | - **A | | | | 32-bit | | | | address | | | | bus can | | | | address | | | | 232=4,294 | | | | ,967,2962\^{32} | | | | = | | | | 4,294,967 | | | | ,296232=4,294,967,296 | | | | (4 GB) | | | | unique | | | | memory | | | | locations | | | |.** | | | | | | | | **Example of Address | | | | Bus Usage** | | | | | | | | **If the CPU needs to | | | | fetch data stored in | | | | memory at address | | | | 0x1000:** | | | | | | | | 1. **It places the | | | | address 0x1000 on | | | | the address | | | | bus.** | | | | | | | | 2. **The memory | | | | identifies this | | | | location and | | | | retrieves or | | | | stores data as | | | | requested.** | | | | | | | | **Diagram:** | | | | | | | | **CPU \-\-\-- Address | | | | Bus \-\-\-- Memory** | | +-----------------------+-----------------------+-----------------------+ | **f)** | **What is a data Bus, | **CO3** | | | explain in details?** | | +-----------------------+-----------------------+-----------------------+ | **Ans.** | **The data bus is | | | | another vital | | | | component of a | | | | computer\'s | | | | communication | | | | architecture. Unlike | | | | the address bus, the | | | | data bus is | | | | bidirectional and is | | | | used for the actual | | |