kopia lustrzana https://github.com/micropython/micropython
105 wiersze
3.5 KiB
C
105 wiersze
3.5 KiB
C
//*****************************************************************************
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//
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// utils.c
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//
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// Utility APIs
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//
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// Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
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//
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions
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// are met:
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//
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// Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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//
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// Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the
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// distribution.
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//
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// Neither the name of Texas Instruments Incorporated nor the names of
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// its contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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//*****************************************************************************
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//*****************************************************************************
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//
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//! \addtogroup Utils_api
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//! @{
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//
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//*****************************************************************************
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#include "utils.h"
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//*****************************************************************************
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//
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//! Provides a small delay.
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//!
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//! \param ulCount is the number of delay loop iterations to perform.
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//!
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//! This function provides a means of generating a constant length delay. It
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//! is written in assembly to keep the delay consistent across tool chains,
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//! avoiding the need to tune the delay based on the tool chain in use.
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//!
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//! The loop takes 3 cycles/loop.
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//!
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//! \return None.
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//
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//*****************************************************************************
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#if defined(ewarm) || defined(DOXYGEN)
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void
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UtilsDelay(unsigned long ulCount)
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{
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__asm(" subs r0, #1\n"
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" bne.n UtilsDelay\n");
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}
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#endif
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#if defined(gcc)
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void __attribute__((naked))
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UtilsDelay(unsigned long ulCount)
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{
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__asm(" subs r0, #1\n"
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" bne UtilsDelay\n"
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" bx lr");
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}
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#endif
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//
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// For CCS implement this function in pure assembly. This prevents the TI
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// compiler from doing funny things with the optimizer.
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//
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#if defined(ccs)
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__asm(" .sect \".text:UtilsDelay\"\n"
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" .clink\n"
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" .thumbfunc UtilsDelay\n"
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" .thumb\n"
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" .global UtilsDelay\n"
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"UtilsDelay:\n"
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" subs r0, #1\n"
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" bne.n UtilsDelay\n"
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" bx lr\n");
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#endif
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//*****************************************************************************
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//
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// Close the Doxygen group.
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//! @}
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//
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//*****************************************************************************
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