[avr-libc-dev] [bug #28881] nop() macro for NOP instruction

[Soren Jorvang]

URL:
  <http://savannah.nongnu.org/bugs/?28881>

                 Summary: nop() macro for NOP instruction
                 Project: AVR C Runtime Library
            Submitted by: soren
            Submitted on: Fri 12 Feb 2010 08:14:55 PM GMT
                Category: Library
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Header files
                  Status: None
        Percent Complete: 90%
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 1.6.7
           Fixed Release: None

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Details:

The special instructions CLI/SEI/SLEEP/WDR each have a convenient macro to
allow their direct use in C.

This patch adds NOP to that list as it can be useful as e.g. a write/read
barrier without any side effects.

util/delay_basic.h as used in the patch may not be the ideal place for it,
but I couldn't find a better, more central place for it in include/avr.

The BREAK instruction added to newer AVR's should probably also have such a
convenience macro added. Again, I am not sure where I think the best place for
it would be or if it should be called something other than just break() to
avoid any confusion with the break keyword.



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File Attachments:


-------------------------------------------------------
Date: Fri 12 Feb 2010 08:14:55 PM GMT  Name: delay_basic.h.diff  Size: 586B  
By: soren

<http://savannah.nongnu.org/bugs/download.php?file_id=19690>

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