micropython/ports/cc3200/hal/utils.c

105 wiersze
3.5 KiB
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.
//! @}
//
//*****************************************************************************