Njs Engineers India Assistant Engineer Interview Questions and Answers

ISR stands for Interrupt Service Routine.

• ISR is a function that is executed in response to an interrupt signal from a hardware device.

• It is used to handle time-critical events and to communicate with hardware devices.

• ISR is commonly used in embedded systems and real-time operating systems.

• Examples of ISR include handling keyboard input, processing network packets, and updating display output.

Interrupt latency is the time delay between the occurrence of an interrupt and the start of the interrupt handler.

• Interrupt latency is an important metric in real-time systems.

• It is measured in microseconds or nanoseconds.

• Interrupt latency can be affected by factors such as hardware design, interrupt priority, and the current state of the processor.

• For example, if a high-priority interrupt occurs while the processor is...read more

++i is faster than i+1

• ++i increments the value of i and returns the new value

• i+1 creates a new value by adding 1 to i and returns it

• ++i is a single operation while i+1 involves two operations

• In some cases, the difference in speed may not be noticeable

A watchdog timer is a hardware or software component that monitors the operation of a system and resets it if necessary.

• It is used to prevent system crashes or malfunctions due to software bugs or hardware failures.

• The timer must be periodically reset by the system to prevent it from triggering a reset.

• If the system fails to reset the timer, it assumes that the system has crashed and triggers a reset.

• Watchdog timers ar...read more

Communication protocols are sets of rules that govern the exchange of data between devices.

• There are various types of communication protocols such as TCP/IP, HTTP, FTP, SMTP, etc.

• TCP/IP is the most commonly used protocol for communication over the internet.

• HTTP is used for communication between web servers and clients.

• FTP is used for file transfer between computers.

• SMTP is used for email communication.

• Communication pro...read more