...implement a FIQ interrupt service routine in C?

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Paul Curtis

• July 13, 2009 12:15

Do I need to do anything special to implement a FIQ interrupt service routine in C?

 

You will need to write the fiq handler in ARM assembly code. You will need to import the device specific _startup.s and crt0.s files into your project. In the crt0.s file you can set the initial values of the FIQ banked registers. In the device specific _startup.s file you can write your fiq_handler.

Your application code will need to program the interrupt controller of the device and call libarm_enable_fiq.

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  Peter Scott

  • June 27, 2010 05:19

  in device specific _startup.s 

  fiq_handler:

  b fiq_service_routine

  simple as that?

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  Jon Elliott

  • June 28, 2010 09:24

  The default exception handlers are usually defined as weak symbols, so you don't need to branch to your FIQ handler from the default handler, you just need to name it fiq_handler and it will be linked in instead of the default handler.

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  Peter Scott

  • October 20, 2010 22:41

  Thanks for being there

   

  but I'm still in trouble getting up a fiq handler

  how are the special fiq registers set in crt0.s ?

  Are there examples of timer driven FIQ setup and test in the literature.

   

  regards

  Peter Scott

   

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  Michael Johnson

  • October 21, 2010 08:57

  You can't use the FIQ registers in a C function. You'll need to assembly code if you want to use the FIQ registers. I can send an example if you want one.

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  Peter Scott

  • October 21, 2010 21:17

  Michael Johnson

  yes please

  i'd like to see an example of timer driven FIQ etc...

   

  regards

  Peter Scott

  pete@comcen.com.au

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  Michael Johnson

  • October 22, 2010 06:44

  I mailed the example to you.

  Regards

  Michael

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  Deng Deng

  • May 13, 2011 13:16

  Hi there,

  I'm currently trying to use the FIQ in C language on LPC2138, but I don't know what needs to be edited in the startup.s file and how to manipulate the fiq_handler function. Can you explain to me briefly and send me an example of FIQ as well? Any help will be much appreciated. :P

  Regards,

  Allen

  dengdeng168@163.com

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  nehal solanki

  • September 01, 2011 18:37

  Hi Michael,

  Can you please send me the example too.

  Thank you.

  nehal

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  Martin Wakely

  • October 05, 2012 10:23

  me too please

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