Table of Contents
How does timer interrupt work?
CTC timer interrupts are triggered when the counter reaches a specified value, stored in the compare match register. Once a timer counter reaches this value it will clear (reset to zero) on the next tick of the timer’s clock, then it will continue to count up to the compare match value again.
What is the use of timer flag interrupt?
Internal interrupt (Timer Interrupt) Whenever timer overflows, timer overflow flags (TF0/TF1) are set. Then the microcontroller jumps to their vector address to serve the interrupt.
What is the role of timer in operating system?
“We can use the timer to prevent a user program from running too long. A simple technique is to initialize a counter with the amount of time that a program is allowed to run. A program with a 7-minute time limit, for example, would have its counter initialized to 420.
What is a process interrupt?
An interrupt is an event that alters the sequence in which the processor executes instructions. These interrupts occur when the operator selects the restart function at the console or when a restart SIGP (signal processor) instruction is received from another processor.
What are the sources of timer interrupt?
Let’s see the five sources of interrupts in 8051 Microcontroller:
- Timer 0 overflow interrupt – TF0.
- External hardware interrupt – INT0.
- Timer 1 overflow interrupt – TF1.
- External hardware interrupt – INT1.
- Serial communication interrupt – RI/TI.
What does timer overflow interrupt mean?
Well, when the timer counter reaches its maximum value in bit – means that if the timer is a 8-bit timer, it can reaches maximum 255 – the timer go back to zero. At this specific moment, the timer overflow interrupt occur. This means that we can do something at the frequency that we want.
What is a scheduling queue?
The processes that are residing in main memory and are ready and waiting to execute are kept on a list called the ready queue. This queue is generally stored as a linked list. A ready-queue header contains pointers to the first and final PCBs in the list.
What is interrupt control in microcontroller?
Interrupts are the events that temporarily suspend the main program, pass the control to the external sources and execute their task. It then passes the control to the main program where it had left off.
What is a clock interrupt?
Clock interrupts (a.k.a. timer interrupts) occur on the order of every millisecond (typically configurable by the OS) and are used to support preemptive multitasking. Being invoked periodically, the OS can decide to allow the current task to continue running or schedule another task.