A mechanism for the control of program flow in a computer. When interrupted a computer saves its present operational state and changes to executing code (interrupt handler) that is dependent upon which interrupt was generated. Interrupts can be either hardware- or software-sourced; software-sourced interrupts are called traps. It is an alternate mechanism to polling and is the basis around which most I/O, multitasking and control is implemented.
Questions tagged [interrupts]
842 questions
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3 answers
What's the actual difference between edge sensitive and level sensitive interrupts
Currently I'm working on a C8051F120 MCU where external interrupts can be defined in two ways:
Edge sensitive (falling)
Level sensitive (low-level)
In level-sensitive interrupts as soon as the MCU detects a low level at the external pin it will…
nkg2743
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votes
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Mutex in interrupts
For a small micro controller without an OS what is the proper way to share data between different interrupts and the main loop?
With an OS one can just create a mutex for each critical part and carry on and the scheduler will switch between tasks…
Carlos
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4 answers
Level vs edge triggering, usefulness of level triggering
Many processors / µCs / dev-platforms (BeagleBoard, Arduino,...) use interrupts.
These can be triggered by the detection of:
HIGH level
RISING edge
CHANGING level (either FALLING or RISING edge)
FALLING edge
LOW level
Now either of two things must…
Mark
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3
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5 answers
ISR - Scope vs. Counter
I have a simple program basically increment the counter every time I get an interrupt. The code is something like this:
void ISR(void)
{
static int counter=0;
counter++;
GPIO_SET(PIN1); // set the gpio pin
DELAY(10); // some short delay so…
Frank
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2
votes
2 answers
Handling interrupts during device communication
I have the following situation:
I was given a AVR32UC3 (pretty neat thing) and a measurement device. These two communicate via SPI, which works as expected (after fiddling with SPI params and so on).
The program structure is as follows:
Init the…
Tom L.
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2
votes
0 answers
MikroC trigger interrupt in compiler
I am trying to test the interrupt function at home without a board to push buttons etc. I gave up on my code and copied an example but still cant make it work. Below is the sample code.
In the while loop it sets the bits on but the interrupt…
Mark Worsnop
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2
votes
2 answers
Interrupt Priorities- What does it actually mean?
I have one generic question regarding interrupts. My software has 2 interrupts,lets say interrupt_x (timer), interrupt_y(spi).
Both interrupt has its own ISR. Interrupt_x has higher priority than interrupt_y. What does assigning priorities actually…
user180742
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2
votes
1 answer
PCF8574T I2C to 8bit Parallel
I want to connect 5 of pcf8574t on my AVR ATMEGA32L. One for LCD 2x16 and 4 for general purpose I/O. The question is: if i get an interrupt signal from one of 4 chips, how can i know which chip has send the interrupt?
I think that circuit may be…
MrBit
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vote
3 answers
Interrupt being called before complete execution of ISR
What happens when an interrupt is called again before the execution of the ISR is completed?
Shreyan Chowdhury
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ATTINY85 interrupt confusion
I'm trying to get ATTINY85 to trigger ONLY on HIGH interrupt, but no matter what combination of bits I set for GIMSK and MCUCR, I can't get it to work;
Here's my code:
#define F_CPU 1000000UL
#include
#include
#include…
0x29a
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0
votes
5 answers
Interrupts: does execution continue afterwards, and how long can they be?
I’ve been reading that interrupt callbacks must be very short. I have two questions:
Imagine the while(1) loop inside the main. I guess this while(1) loops with clock frequency(?). Does this looping stop when the interrupt occurs and resume when…
GNZ
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GPIO external interrupt on LPC1769
I am working on GPIO external interrupt on LPC1769 board and having problems getting it to work. I have connected pin 2.11 to a push button and interrupt must be generated when the button is pushed. Any help is greatly appreciated. Thanks.. Below is…
storm_rd
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votes
4 answers
Difference between priority and vector table
Is their any difference between interrupt vector table and priority table. Does the vector node simply tells its priority? Here is the vector table:
user123456
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