# ARM Sam7s Task switch

**URL:** <https://forums.freertos.org/t/arm-sam7s-task-switch/2101>\
**Category:** Kernel\
**Created:** [August 7, 2006, 10:24am UTC](https://forums.freertos.org/t/arm-sam7s-task-switch/2101 "2006-08-07T10:24:08Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [August 7, 2006, 10:24am UTC](https://forums.freertos.org/t/arm-sam7s-task-switch/2101/1 "2006-08-07T10:24:08Z")

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**nobody** wrote on [Monday, August 07, 2006](https://sourceforge.net/p/freertos/discussion/382005/thread/5d7ad67b/#1c91):

Hi,

does anybody knows what happens if a vPortYieldProcessor or vPortPreemptiveTick event interrupts each other?  
Can this cause any problems. The interrupt is not blocked inside this code (3.2.2)

Regards

Rainer

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<div class="post-metadata">

**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [August 7, 2006, 10:53am UTC](https://forums.freertos.org/t/arm-sam7s-task-switch/2101/2 "2006-08-07T10:53:34Z")

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**nobody** wrote on [Monday, August 07, 2006](https://sourceforge.net/p/freertos/discussion/382005/thread/5d7ad67b/#1c91/3f1f):

vPortYieldProcessor and vPortPreemptiveTick both execute from within an interrupt (SWI and IRQ respectively).&nbsp; In the [FreeRTOS.org](http://FreeRTOS.org) demos interrupts remain masked for their entire execution so they cannot interrupt each other.&nbsp;

If this is not the case for your project then you must have rewritten the interrupt entry and exit code???