<html lang="en"> <head> <title>MSP430 Built-in Functions - Using the GNU Compiler Collection (GCC)</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Using the GNU Compiler Collection (GCC)"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Target-Builtins.html#Target-Builtins" title="Target Builtins"> <link rel="prev" href="Other-MIPS-Built_002din-Functions.html#Other-MIPS-Built_002din-Functions" title="Other MIPS Built-in Functions"> <link rel="next" href="NDS32-Built_002din-Functions.html#NDS32-Built_002din-Functions" title="NDS32 Built-in Functions"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- Copyright (C) 1988-2015 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being ``Funding Free Software'', the Front-Cover Texts being (a) (see below), and with the Back-Cover Texts being (b) (see below). A copy of the license is included in the section entitled ``GNU Free Documentation License''. (a) The FSF's Front-Cover Text is: A GNU Manual (b) The FSF's Back-Cover Text is: You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development.--> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="MSP430-Built-in-Functions"></a> <a name="MSP430-Built_002din-Functions"></a> <p> Next: <a rel="next" accesskey="n" href="NDS32-Built_002din-Functions.html#NDS32-Built_002din-Functions">NDS32 Built-in Functions</a>, Previous: <a rel="previous" accesskey="p" href="Other-MIPS-Built_002din-Functions.html#Other-MIPS-Built_002din-Functions">Other MIPS Built-in Functions</a>, Up: <a rel="up" accesskey="u" href="Target-Builtins.html#Target-Builtins">Target Builtins</a> <hr> </div> <h4 class="subsection">6.58.16 MSP430 Built-in Functions</h4> <p>GCC provides a couple of special builtin functions to aid in the writing of interrupt handlers in C. <dl> <dt><code>__bic_SR_register_on_exit (int </code><var>mask</var><code>)</code><dd>This clears the indicated bits in the saved copy of the status register currently residing on the stack. This only works inside interrupt handlers and the changes to the status register will only take affect once the handler returns. <br><dt><code>__bis_SR_register_on_exit (int </code><var>mask</var><code>)</code><dd>This sets the indicated bits in the saved copy of the status register currently residing on the stack. This only works inside interrupt handlers and the changes to the status register will only take affect once the handler returns. <br><dt><code>__delay_cycles (long long </code><var>cycles</var><code>)</code><dd>This inserts an instruction sequence that takes exactly <var>cycles</var> cycles (between 0 and about 17E9) to complete. The inserted sequence may use jumps, loops, or no-ops, and does not interfere with any other instructions. Note that <var>cycles</var> must be a compile-time constant integer - that is, you must pass a number, not a variable that may be optimized to a constant later. The number of cycles delayed by this builtin is exact. </dl> </body></html>