flash.c

基于 Cortex-M3 (ARM) 内核使用之 uC/OS-II 作业系统,此例程可移植于 Cortex-M3 (ARM)内核的微处理器上的应用,于 Keil MDK 3.15b以上 工程编译,而

    // Check the argument.
    //
    ASSERT(!(ulAddress & (FLASH_PROTECT_SIZE - 1)));
    ASSERT((eProtect == FlashReadWrite) || (eProtect == FlashReadOnly) ||
           (eProtect == FlashExecuteOnly));

    //
    // Convert the address into a block number.
    //
    ulAddress /= FLASH_PROTECT_SIZE;

    //
    // Get the current protection.
    //
    ulProtectRE = HWREG(FLASH_FMPRE);
    ulProtectPE = HWREG(FLASH_FMPPE);

    //
    // Set the protection based on the requested proection.
    //
    switch(eProtect)
    {
        //
        // Make this block execute only.
        //
        case FlashExecuteOnly:
        {
            //
            // Turn off the read and program bits for this block.
            //
            ulProtectRE &= ~(FLASH_FMP_BLOCK_0 << ulAddress);
            ulProtectPE &= ~(FLASH_FMP_BLOCK_0 << ulAddress);

            //
            // We're done handling this protection.
            //
            break;
        }

        //
        // Make this block read only.
        //
        case FlashReadOnly:
        {
            //
            // The block can not be made read only if it is execute only.
            //
            if(((ulProtectRE >> ulAddress) & FLASH_FMP_BLOCK_0) !=
               FLASH_FMP_BLOCK_0)
            {
                return(-1);
            }

            //
            // Make this block read only.
            //
            ulProtectPE &= ~(FLASH_FMP_BLOCK_0 << ulAddress);

            //
            // We're done handling this protection.
            //
            break;
        }

        //
        // Make this block read/write.
        //
        case FlashReadWrite:
        default:
        {
            //
            // The block can not be made read/write if it is not already
            // read/write.
            //
            if((((ulProtectRE >> ulAddress) & FLASH_FMP_BLOCK_0) !=
                FLASH_FMP_BLOCK_0) ||
               (((ulProtectPE >> ulAddress) & FLASH_FMP_BLOCK_0) !=
                FLASH_FMP_BLOCK_0))
            {
                return(-1);
            }

            //
            // The block is already read/write, so there is nothing to do.
            //
            return(0);
        }
    }

    //
    // Set the new protection.
    //
    HWREG(FLASH_FMPRE) = ulProtectRE;
    HWREG(FLASH_FMPPE) = ulProtectPE;

    //
    // Success.
    //
    return(0);
}

//*****************************************************************************
//
//! Saves the flash protection settings.
//!
//! This function will make the currently programmed flash protection settings
//! permanent.  This is a non-reversible operation; a chip reset or power cycle
//! will not change the flash protection.
//!
//! This function will not return until the protection has been saved.
//!
//! \return Returns 0 on success, or -1 if a hardware error is encountered.
//
//*****************************************************************************
long
FlashProtectSave(void)
{
    //
    // Tell the flash controller to write the flash read protection register.
    //
    HWREG(FLASH_FMA) = 0;
    HWREG(FLASH_FMC) = FLASH_FMC_WRKEY | FLASH_FMC_COMT;

    //
    // Wait until the write has completed.
    //
    while(HWREG(FLASH_FMC) & FLASH_FMC_COMT)
    {
    }

    //
    // Tell the flash controller to write the flash program protection
    // register.
    //
    HWREG(FLASH_FMA) = 1;
    HWREG(FLASH_FMC) = FLASH_FMC_WRKEY | FLASH_FMC_COMT;

    //
    // Wait until the write has completed.
    //
    while(HWREG(FLASH_FMC) & FLASH_FMC_COMT)
    {
    }

    //
    // Success.
    //
    return(0);
}

//*****************************************************************************
//
//! Registers an interrupt.handler for the flash interrupt.
//!
//! \param pfnHandler is a pointer to the function to be called when the flash
//! interrupt occurs.
//!
//! This sets the handler to be called when the flash interrupt occurs.  The
//! flash controller can generate an interrupt when an invalid flash access
//! occurs, such as trying to program or erase a read-only block, or trying to
//! read from an execute-only block.  It can also generate an interrupt when a
//! program or erase operation has completed.  The interrupt will be
//! automatically enabled when the handler is registered.
//!
//! \sa IntRegister() for important information about registering interrupt
//! handlers.
//!
//! \return None.
//
//*****************************************************************************
void
FlashIntRegister(void (*pfnHandler)(void))
{
    //
    // Register the interrupt.handler, returning an error if an error occurs.
    //
    IntRegister(INT_FLASH, pfnHandler);

    //
    // Enable the flash interrupt.
    //
    IntEnable(INT_FLASH);
}

//*****************************************************************************
//
//! Unregisters the interrupt.handler for the flash interrupt.
//!
//! This function will clear the handler to be called when the flash interrupt
//! occurs.  This will also mask off the interrupt in the interrupt controller
//! so that the interrupt.handler is no longer called.
//!
//! \sa IntRegister() for important information about registering interrupt
//! handlers.
//!
//! \return None.
//
//*****************************************************************************
void
FlashIntUnregister(void)
{
    //
    // Disable the interrupt.
    //
    IntDisable(INT_FLASH);

    //
    // Unregister the interrupt.handler.
    //
    IntUnregister(INT_FLASH);
}

//*****************************************************************************
//
//! Enables individual flash controller interrupt sources.
//!
//! \param ulIntFlags is a bit mask of the interrupt sources to be enabled.
//! Can be any of the \b FLASH_FCIM_PROGRAM or \b FLASH_FCIM_ACCESS values.
//!
//! Enables the indicated flash controller interrupt sources.  Only the sources
//! that are enabled can be reflected to the processor interrupt; disabled
//! sources have no effect on the processor.
//!
//! \return None.
//
//*****************************************************************************
void
FlashIntEnable(unsigned long ulIntFlags)
{
    //
    // Enable the specified interrupts.
    //
    HWREG(FLASH_FCIM) |= ulIntFlags;
}

//*****************************************************************************
//
//! Disables individual flash controller interrupt sources.
//!
//! \param ulIntFlags is a bit mask of the interrupt sources to be disabled.
//! Can be any of the \b FLASH_FCIM_PROGRAM or \b FLASH_FCIM_ACCESS values.
//!
//! Disables the indicated flash controller interrupt sources.  Only the
//! sources that are enabled can be reflected to the processor interrupt;
//! disabled sources have no effect on the processor.
//!
//! \return None.
//
//*****************************************************************************
void
FlashIntDisable(unsigned long ulIntFlags)
{
    //
    // Disable the specified interrupts.
    //
    HWREG(FLASH_FCIM) &= ~(ulIntFlags);
}

//*****************************************************************************
//
//! Gets the current interrupt status.
//!
//! \param bMasked is false if the raw interrupt status is required and true if
//! the masked interrupt status is required.
//!
//! This returns the interrupt status for the flash controller.  Either the raw
//! interrupt status or the status of interrupts that are allowed to reflect to
//! the processor can be returned.
//!
//! \return The current interrupt status, enumerated as a bit field of
//! \b FLASH_FCMISC_PROGRAM and \b FLASH_FCMISC_ACCESS.
//
//*****************************************************************************
unsigned long
FlashIntGetStatus(tBoolean bMasked)
{
    //
    // Return either the interrupt status or the raw interrupt status as
    // requested.
    //
    if(bMasked)
    {
        return(HWREG(FLASH_FCMISC));
    }
    else
    {
        return(HWREG(FLASH_FCRIS));
    }
}

//*****************************************************************************
//
//! Clears flash controller interrupt sources.
//!
//! \param ulIntFlags is the bit mask of the interrupt sources to be cleared.
//! Can be any of the \b FLASH_FCMISC_PROGRAM or \b FLASH_FCMISC_ACCESS
//! values.
//!
//! The specified flash controller interrupt sources are cleared, so that they
//! no longer assert.  This must be done in the interrupt.handler to keep it
//! from being called again immediately upon exit.
//!
//! \return None.
//
//*****************************************************************************
void
FlashIntClear(unsigned long ulIntFlags)
{
    //
    // Clear the flash interrupt.
    //
    HWREG(FLASH_FCMISC) = ulIntFlags;
}

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