fpu.c

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//*****************************************************************************
//
// fpu.c - Routines for manipulating the floating-point unit in the Cortex-M
//         processor.
//
// Copyright (c) 2011-2014 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
//   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,
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// 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.
// 
// This is part of revision 2.1.0.12573 of the Tiva Peripheral Driver Library.
//
//*****************************************************************************

//*****************************************************************************
//
//
//*****************************************************************************

#include <stdint.h>
#include "inc/hw_nvic.h"
#include "inc/hw_types.h"
#include "driverlib/fpu.h"

//*****************************************************************************
//
//
//*****************************************************************************
void
FPUEnable(void)
{
    //
    // Enable the coprocessors used by the floating-point unit.
    //
    HWREG(NVIC_CPAC) = ((HWREG(NVIC_CPAC) &
                         ~(NVIC_CPAC_CP10_M | NVIC_CPAC_CP11_M)) |
                        NVIC_CPAC_CP10_FULL | NVIC_CPAC_CP11_FULL);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPUDisable(void)
{
    //
    // Disable the coprocessors used by the floating-point unit.
    //
    HWREG(NVIC_CPAC) = ((HWREG(NVIC_CPAC) &
                         ~(NVIC_CPAC_CP10_M | NVIC_CPAC_CP11_M)) |
                        NVIC_CPAC_CP10_DIS | NVIC_CPAC_CP11_DIS);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPUStackingEnable(void)
{
    //
    // Enable automatic state preservation for the floating-point unit, and
    // disable lazy state preservation (meaning that the floating-point state
    // is always stacked when floating-point instructions are used).
    //
    HWREG(NVIC_FPCC) = (HWREG(NVIC_FPCC) & ~NVIC_FPCC_LSPEN) | NVIC_FPCC_ASPEN;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPULazyStackingEnable(void)
{
    //
    // Enable automatic and lazy state preservation for the floating-point
    // unit.
    //
    HWREG(NVIC_FPCC) |= NVIC_FPCC_ASPEN | NVIC_FPCC_LSPEN;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPUStackingDisable(void)
{
    //
    // Disable automatic and lazy state preservation for the floating-point
    // unit.
    //
    HWREG(NVIC_FPCC) &= ~(NVIC_FPCC_ASPEN | NVIC_FPCC_LSPEN);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPUHalfPrecisionModeSet(uint32_t ui32Mode)
{
    //
    // Set the half-precision floating-point format.
    //
    HWREG(NVIC_FPDSC) = (HWREG(NVIC_FPDSC) & ~(NVIC_FPDSC_AHP)) | ui32Mode;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPUNaNModeSet(uint32_t ui32Mode)
{
    //
    // Set the NaN mode.
    //
    HWREG(NVIC_FPDSC) = (HWREG(NVIC_FPDSC) & ~(NVIC_FPDSC_DN)) | ui32Mode;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPUFlushToZeroModeSet(uint32_t ui32Mode)
{
    //
    // Set the flush-to-zero mode.
    //
    HWREG(NVIC_FPDSC) = (HWREG(NVIC_FPDSC) & ~(NVIC_FPDSC_FZ)) | ui32Mode;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
FPURoundingModeSet(uint32_t ui32Mode)
{
    //
    // Set the rounding mode.
    //
    HWREG(NVIC_FPDSC) = (HWREG(NVIC_FPDSC) & ~(NVIC_FPDSC_RMODE_M)) | ui32Mode;
}

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//
// Close the Doxygen group.
//
//*****************************************************************************