ThoughtWorks Most Frequently Asked Latest Linux Interview Questions Answers
Explain What Is Microcontroller?
The microcontroller is a self-contained system with peripherals, memory and a processor that can be used as embedded system.
Mention What Is The Difference Between Microprocessor And Microcontroller?
Microprocessor is managers of the resources (I/O, memory) which lie outside of its architecture Microcontroller have I/O, memory, etc. built into it and specifically designed for control.
What Does Dma Address Will Deal With?
DMA address deals with physical addresses. It is a device which directly drives the data and address bus during data transfer. So, it is purely physical address.
Explain Interrupt Latency And How Can We Decrease It?
1.Interrupt latency basically refers to the time span an interrupt is generated and it being serviced by an appropriate routine defined, usually the interrupt handler.
2.External signals, some condition in the program or by the occurrence of some event, these could be the reasons for generation of an interrupt.
3.Interrupts can also be masked so as to ignore them even if an event occurs for which a routine has to be executed.
4.Following steps could be followed to reduce the latency
•ISRs being simple and short.
•Interrupts being serviced immediately
•Avoiding those instructions that increase the latency period.
•Also by prioritizing interrupts over threads.
•Avoiding use of inappropriate APIs.
How To Create A Child Process In Linux?
Prototype of the function used to create a child process is pid_t fork(void);
•Fork is the system call that is used to create a child process. It takes no arguments and returns a value of type pid_t.
•If the function succeeds it returns the pid of the child process created to its parent and child receives a zero value indicating its successful creation.
•On failure, a -1 will be returned in the parent's context, no child process will be created, and errno will be set.
•The child process normally performs all its operations in its parents context but each process independently of one nother and also inherits some of the important attributes from it such as UID, current directory, root directory and so on.
Significance of watchdog timer in Embedded Systems.
•Watchdog timer is basically a timing device that is set for predefined time interval and some event should occur during that time interval else the device generates a time out signal.
•One application where it is most widely used is when the mobile phone hangs and no activity takes place, in those cases watchdog timer performs a restart of the system and comes to the rescue of the users.
•It is used to reset to the original state whenever some inappropriate events take place such as too many commands being given at the same time or other activities that result in malfunctioning of the GUI. It is usually operated by counter devices.
What Is The Difference Between Hardware Design And Software Design?
•Hardware design is designed with the collaboration of interconnected parallel components that inherits the properties of each other. Whereas, Software design is designed with sequential components, that are based on objects and threads.
•Hardware design structure doesn’t change dynamically and it can’t be created, modified or removed easily. Whereas, Software design structure can be changed dynamically and re-usability features, used to define the components. It also includes easy creation, modification and removal of the components from the software.
Explain What Is Interrupt Latency? How Can You Reduce It?
Interrupt latency is a time taken to return from the interrupt service routine post handling a specific interrupt. By writing minor ISR routines, interrupt latency can be reduced.
Mention What Are Buses Used For Communication In Embedded System?
For embedded system, the buses used for communication includes
• I2C: It is used for communication between multiple ICs
• CAN: It is used in automobiles with centrally controlled network
• USB: It is used for communication between CPU and devices like mouse, etc.
While ISA, EISA, PCI are standard buses for parallel communication used in PCs, computer network devices, etc.
List Out Various Uses Of Timers In Embedded System?
Timers in embedded system are used in multiple ways
• Real Time Clock (RTC) for the system
• Initiating an event after a preset time delay
• Initiating an even after a comparison of preset times
• Capturing the count value in timer on an event
• Between two events finding the time interval
• Time slicing for various tasks
• Time division multiplexing
• Scheduling of various tasks in RTOS
Explain What Is A Watchdog Timer?
A watchdog timer is an electronic device or electronic card that execute specific operation after certain time period if something goes wrong with an electronic system.
Explain What Is Embedded System In A Computer System?
An embedded system is a computer system that is part of a larger system or machine. It is a system with a dedicated function within a larger electrical or mechanical system.
Mention What Are The Essential Components Of Embedded System?
Essential components of embedded system includes
•Hardware
•Processor
•Memory
•Timers
•I/O circuits
•System application specific circuits
•Software
•It ensures the availability of System Memory
•It checks the Processor Speed availability
•The need to limit power lost when running the system continuously
•Real Time Operating System
•It runs a process as per scheduling and do the switching from one process to another
Why Embedded System Is Useful?
With embedded system, it is possible to replace dozens or even more of hardware logic gates, input buffers, timing circuits, output drivers, etc. with a relatively cheap microprocessor.
Explain What Are Real-time Embedded Systems?
Real-time embedded systems are computer systems that monitor, respond or control an external environment. This environment is connected to the computer system through actuators, sensors, and other input-output interfaces.
Explain What Is The Need For An Infinite Loop In Embedded Systems?
Embedded systems require infinite loops for repeatedly processing or monitoring the state of the program. For instance, the case of a program state continuously being verified for any exceptional errors that might just happen during run-time such as memory outage or divide by zero, etc.
Explain What Is Microcontroller?
The microcontroller is a self-contained system with peripherals, memory and a processor that can be used as embedded system.
Mention What Is The Difference Between Microprocessor And Microcontroller?
Microprocessor is managers of the resources (I/O, memory) which lie outside of its architecture Microcontroller have I/O, memory, etc. built into it and specifically designed for control.
What Does Dma Address Will Deal With?
DMA address deals with physical addresses. It is a device which directly drives the data and address bus during data transfer. So, it is purely physical address.
Explain Interrupt Latency And How Can We Decrease It?
1.Interrupt latency basically refers to the time span an interrupt is generated and it being serviced by an appropriate routine defined, usually the interrupt handler.
2.External signals, some condition in the program or by the occurrence of some event, these could be the reasons for generation of an interrupt.
3.Interrupts can also be masked so as to ignore them even if an event occurs for which a routine has to be executed.
4.Following steps could be followed to reduce the latency
•ISRs being simple and short.
•Interrupts being serviced immediately
•Avoiding those instructions that increase the latency period.
•Also by prioritizing interrupts over threads.
•Avoiding use of inappropriate APIs.
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| ThoughtWorks Most Frequently Asked Latest Linux Interview Questions Answers |
How To Create A Child Process In Linux?
Prototype of the function used to create a child process is pid_t fork(void);
•Fork is the system call that is used to create a child process. It takes no arguments and returns a value of type pid_t.
•If the function succeeds it returns the pid of the child process created to its parent and child receives a zero value indicating its successful creation.
•On failure, a -1 will be returned in the parent's context, no child process will be created, and errno will be set.
•The child process normally performs all its operations in its parents context but each process independently of one nother and also inherits some of the important attributes from it such as UID, current directory, root directory and so on.
Significance of watchdog timer in Embedded Systems.
•Watchdog timer is basically a timing device that is set for predefined time interval and some event should occur during that time interval else the device generates a time out signal.
•One application where it is most widely used is when the mobile phone hangs and no activity takes place, in those cases watchdog timer performs a restart of the system and comes to the rescue of the users.
•It is used to reset to the original state whenever some inappropriate events take place such as too many commands being given at the same time or other activities that result in malfunctioning of the GUI. It is usually operated by counter devices.
What Is The Difference Between Hardware Design And Software Design?
•Hardware design is designed with the collaboration of interconnected parallel components that inherits the properties of each other. Whereas, Software design is designed with sequential components, that are based on objects and threads.
•Hardware design structure doesn’t change dynamically and it can’t be created, modified or removed easily. Whereas, Software design structure can be changed dynamically and re-usability features, used to define the components. It also includes easy creation, modification and removal of the components from the software.
•Hardware design focuses on individual components that are represented using analytical model that uses the transfer functions. Whereas, Software design represent the components using computation model that can have abstract execution engine or it can use the virtual machine that are non-deterministic.
Explain What Is Interrupt Latency? How Can You Reduce It?
Interrupt latency is a time taken to return from the interrupt service routine post handling a specific interrupt. By writing minor ISR routines, interrupt latency can be reduced.
Mention What Are Buses Used For Communication In Embedded System?
For embedded system, the buses used for communication includes
• I2C: It is used for communication between multiple ICs
• CAN: It is used in automobiles with centrally controlled network
• USB: It is used for communication between CPU and devices like mouse, etc.
While ISA, EISA, PCI are standard buses for parallel communication used in PCs, computer network devices, etc.
List Out Various Uses Of Timers In Embedded System?
Timers in embedded system are used in multiple ways
• Real Time Clock (RTC) for the system
• Initiating an event after a preset time delay
• Initiating an even after a comparison of preset times
• Capturing the count value in timer on an event
• Between two events finding the time interval
• Time slicing for various tasks
• Time division multiplexing
• Scheduling of various tasks in RTOS
Explain What Is A Watchdog Timer?
A watchdog timer is an electronic device or electronic card that execute specific operation after certain time period if something goes wrong with an electronic system.
Explain What Is Embedded System In A Computer System?
An embedded system is a computer system that is part of a larger system or machine. It is a system with a dedicated function within a larger electrical or mechanical system.
Mention What Are The Essential Components Of Embedded System?
Essential components of embedded system includes
•Hardware
•Processor
•Memory
•Timers
•I/O circuits
•System application specific circuits
•Software
•It ensures the availability of System Memory
•It checks the Processor Speed availability
•The need to limit power lost when running the system continuously
•Real Time Operating System
•It runs a process as per scheduling and do the switching from one process to another
Why Embedded System Is Useful?
With embedded system, it is possible to replace dozens or even more of hardware logic gates, input buffers, timing circuits, output drivers, etc. with a relatively cheap microprocessor.
Explain What Are Real-time Embedded Systems?
Real-time embedded systems are computer systems that monitor, respond or control an external environment. This environment is connected to the computer system through actuators, sensors, and other input-output interfaces.
Embedded systems require infinite loops for repeatedly processing or monitoring the state of the program. For instance, the case of a program state continuously being verified for any exceptional errors that might just happen during run-time such as memory outage or divide by zero, etc.
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