Table of Contents
Why are timer interrupts necessary?
Real-Time Operating System A timer interrupt causes the task switching, but interrupts are otherwise not used. When a task is suspended, its context (file register state) is saved and restored when it is restarted the next time around.
What is the use of timer in microprocessor?
The timer is an important application in Embedded systems, it maintains the timing of an operation in sync with a system clock or an external clock. The timer has so many applications such as measure time generating delays, they can also be used for generating baud rates.
Why do we use timers?
A timer is a specialized type of clock which is used to measure time intervals. It is a device that counts down from a specified time interval and used to generate a time delay, for example, an hourglass is a timer.
Why timer is used during a process execution?
We must ensure that the operating system maintains control over the CPU. We must prevent a user program from getting stuck in an infinite loop or not calling system services and never returning control to the operating system. To accomplish this goal, we can use a timer.
What are interrupts and timers?
These are similar to external interrupts, but instead of firing on an external event, they fire on a timer. They are so called as they will intterupt the thread of execution after the current instruction completes, and run their code, returning to the next instruction from where it left off when it has finished.
What is timer interrupt in 8051?
Internal interrupt (Timer Interrupt) 8051 has two internal interrupts namely timer0 and timer1. Whenever timer overflows, timer overflow flags (TF0/TF1) are set. Then the microcontroller jumps to their vector address to serve the interrupt. For this, global and timer interrupt should be enabled.
Do microprocessors have timers?
Timer Basics. Most timers in a modern microprocessor will have more than two registers that dictate the behavior of the timer, but we can use these two registers to examine how timers allow us to measure a precise duration of time.
What is a timer interrupt?
Timer interrupts allow you to perform a task at very specifically timed intervals regardless of what else is going on in your code.
What is the use of timer mode control register in 8051?
Timer Control Register (TCON): TCON is another register used to control operations of counter and timers in microcontrollers. It is an 8-bit register wherein four upper bits are responsible for timers and counters and lower bits are responsible for interrupts.
What is interrupt in timer?
How can timer be used to protect CPU?
CPU protection: CPU usage is protected by using the timer device, the associated timer interrupts, and OS code called the scheduler. While running in user mode, the CPU cannot change the timer value or turn off the timer interrupt, because these require privileged operations.