Arduino/esp8266/micropython/ports/cc3200/hal/utils.c

//*****************************************************************************
//
//  utils.c
//
//  Utility APIs
//
//  Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
//
//
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions
//  are met:
//
//    Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
//    Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the
//    distribution.
//
//    Neither the name of Texas Instruments Incorporated nor the names of
//    its contributors may be used to endorse or promote products derived
//    from this software without specific prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
//  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
//  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
//  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
//  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
//  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
//  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
//  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
//  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//*****************************************************************************

//*****************************************************************************
//
//! \addtogroup Utils_api
//! @{
//
//*****************************************************************************
#include "utils.h"


//*****************************************************************************
//
//! Provides a small delay.
//!
//! \param ulCount is the number of delay loop iterations to perform.
//!
//! This function provides a means of generating a constant length delay.  It
//! is written in assembly to keep the delay consistent across tool chains,
//! avoiding the need to tune the delay based on the tool chain in use.
//!
//! The loop takes 3 cycles/loop.
//!
//! \return None.
//
//*****************************************************************************
#if defined(ewarm) || defined(DOXYGEN)
void
UtilsDelay(unsigned long ulCount)
{
    __asm("    subs    r0, #1\n"
          "    bne.n   UtilsDelay\n");
}
#endif

#if defined(gcc)
void __attribute__((naked))
UtilsDelay(unsigned long ulCount)
{
    __asm("    subs    r0, #1\n"
          "    bne     UtilsDelay\n"
          "    bx      lr");
}
#endif

//
// For CCS implement this function in pure assembly.  This prevents the TI
// compiler from doing funny things with the optimizer.
//
#if defined(ccs)
    __asm("    .sect \".text:UtilsDelay\"\n"
          "    .clink\n"
          "    .thumbfunc UtilsDelay\n"
          "    .thumb\n"
          "    .global UtilsDelay\n"
          "UtilsDelay:\n"
          "    subs r0, #1\n"
          "    bne.n UtilsDelay\n"
          "    bx lr\n");
#endif

//*****************************************************************************
//
// Close the Doxygen group.
//! @}
//
//*****************************************************************************