bugAVR C Runtime Library - Bugs: bug #19178, Propose: Exact-Delay

 
 

You are not allowed to post comments on this tracker with your current authentication level.

bug #19178: Propose: Exact-Delay

Submitter:  Michael Heidinger <overthere>
Submitted:  Thu 01 Mar 2007 01:51:26 PM UTC
   
 
Category:  Feature Request Severity:  1 - Wish
Priority:  3 - Low Item Group:  libc code
Status:  Fixed Assigned to:  joerg_wunsch
Percent Complete:  0% Open/Closed:  Closed
Release:  Any Fixed Release:  None

Wed 09 Jun 2010 08:16:28 AM UTC, comment #1: 

Provided you are using a patched compiler (the patch is
supposed to be integrated into GCC some day), you can get
exactly this with the function

__builtin_avr_delay_cycles()

which has been documented by <avr/builtins.h> for some time
now.  Exact delays for very short cycle counts must be
provided by the compiler rather than the library, as the
overhead to setup the delay has to be taken into account,
and this overhead is only known to the compiler.

Joerg Wunsch <joerg_wunsch>
Group administrator
Thu 01 Mar 2007 01:51:26 PM UTC, original submission:  

Hi,

as I cannot add any proposes, I would like to propose a new macro for the lib in the support-area.

For some applications you need exact delays. delay.h already exists, but this workes with a timer and is not that exact if you need only a delay of 2-15 clocks.

I was trying to realize this with defines, but this makes the source not readable.

Whats about a function "exact_delay(20);" and the lib calculates the waiting? 20 means 20 clocks.

Please realize my propose.

Thanks

Michael Heidinger

Michael Heidinger <overthere>

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -email is unavailable- added by joerg_wunsch (Posted a comment)
  • -email is unavailable- added by arcanum (Updated the item)
  • -email is unavailable- added by overthere (Submitted the item)
  •  

    Follow 8 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2010-06-09 joerg_wunsch StatusNone Fixed
        Assigned toNone joerg_wunsch
        Open/ClosedOpen Closed
        ReleaseNone Any
    2008-03-17 arcanum CategoryLibrary Feature Request
        Severity3 - Normal 1 - Wish
        Priority5 - Normal 3 - Low
    2007-03-01 overthere Carbon-Copy- Added overthere

    Back to the top

    Powered by Savane 3.13-caa5.
    Corresponding source code