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//*****************************************************************************
//
// interrupt.c - Driver for the NVIC Interrupt Controller.
//
// Copyright (c) 2005,2006 Luminary Micro, Inc. All rights reserved.
//
// Software License Agreement
//
// Luminary Micro, Inc. (LMI) is supplying this software for use solely and
// exclusively on LMI's Stellaris Family of microcontroller products.
//
// The software is owned by LMI and/or its suppliers, and is protected under
// applicable copyright laws. All rights are reserved. Any use in violation
// of the foregoing restrictions may subject the user to criminal sanctions
// under applicable laws, as well as to civil liability for the breach of the
// terms and conditions of this license.
//
// THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
// LMI SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
// CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
//
// This is part of revision 991 of the Stellaris Driver Library.
//
//*****************************************************************************
//*****************************************************************************
//
//! \addtogroup interrupt_api
//! @{
//
//*****************************************************************************
#include "../hw_ints.h"
#include "../hw_nvic.h"
#include "../hw_types.h"
#include "cpu.h"
#include "debug.h"
#include "interrupt.h"
//*****************************************************************************
//
// This is a mapping between priority grouping encodings and the number of
// preemption priority bits.
//
//*****************************************************************************
#if defined(GROUP_pulpriority) || defined(BUILD_ALL)
const unsigned long g_pulPriority[] =
{
NVIC_APINT_PRIGROUP_0_8, NVIC_APINT_PRIGROUP_1_7, NVIC_APINT_PRIGROUP_2_6,
NVIC_APINT_PRIGROUP_3_5, NVIC_APINT_PRIGROUP_4_4, NVIC_APINT_PRIGROUP_5_3,
NVIC_APINT_PRIGROUP_6_2, NVIC_APINT_PRIGROUP_7_1
};
#else
extern const unsigned long g_pulPriority[];
#endif
//*****************************************************************************
//
// This is a mapping between interrupt number and the register that contains
// the priority encoding for that interrupt.
//
//*****************************************************************************
#if defined(GROUP_pulregs) || defined(BUILD_ALL)
const unsigned long g_pulRegs[12] =
{
0, NVIC_SYS_PRI1, NVIC_SYS_PRI2, NVIC_SYS_PRI3, NVIC_PRI0, NVIC_PRI1,
NVIC_PRI2, NVIC_PRI3, NVIC_PRI4, NVIC_PRI5, NVIC_PRI6, NVIC_PRI7
};
#else
extern const unsigned long g_pulRegs[12];
#endif
//*****************************************************************************
//
//! \internal
//! The default interrupt handler.
//!
//! This is the default interrupt handler for all interrupts. It simply loops
//! forever so that the system state is preserved for observation by a
//! debugger. Since interrupts should be disabled before unregistering the
//! corresponding handler, this should never be called.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_defaulthandler) || defined(BUILD_ALL)
void
IntDefaultHandler(void)
{
//
// Go into an infinite loop.
//
while(1)
{
}
}
#else
extern void IntDefaultHandler(void);
#endif
//*****************************************************************************
//
// The processor vector table.
//
// This contains a list of the handlers for the various interrupt sources in
// the system. The layout of this list is defined by the hardware; assertion
// of an interrupt causes the processor to start executing directly at the
// address given in the corresponding location in this list.
//
//*****************************************************************************
#if defined(GROUP_vtable) || defined(BUILD_ALL)
#ifdef ewarm
__no_init void (*g_pfnRAMVectors[NUM_INTERRUPTS])(void) @ "VTABLE";
#else
__attribute__((section("vtable")))
void (*g_pfnRAMVectors[NUM_INTERRUPTS])(void);
#endif
#else
extern void (*g_pfnRAMVectors[NUM_INTERRUPTS])(void);
#endif
//*****************************************************************************
//
//! Enables the processor interrupt.
//!
//! Allows the processor to respond to interrupts. This does not affect the
//! set of interrupts enabled in the interrupt controller; it just gates the
//! single interrupt from the controller to the processor.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_masterenable) || defined(BUILD_ALL) || defined(DOXYGEN)
void
IntMasterEnable(void)
{
//
// Enable processor interrupts.
//
CPUcpsie();
}
#endif
//*****************************************************************************
//
//! Disables the processor interrupt.
//!
//! Prevents the processor from receiving interrupts. This does not affect the
//! set of interrupts enabled in the interrupt controller; it just gates the
//! single interrupt from the controller to the processor.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_masterdisable) || defined(BUILD_ALL) || defined(DOXYGEN)
void
IntMasterDisable(void)
{
//
// Disable processor interrupts.
//
CPUcpsid();
}
#endif
//*****************************************************************************
//
//! Registers a function to be called when an interrupt occurs.
//!
//! \param ulInterrupt specifies the interrupt in question.
//! \param pfnHandler is a pointer to the function to be called.
//!
//! This function is used to specify the handler function to be called when the
//! given interrupt is asserted to the processor. When the interrupt occurs,
//! if it is enabled (via IntEnable()), the handler function will be called in
//! interrupt context. Since the handler function can preempt other code, care
//! must be taken to protect memory or peripherals that are accessed by the
//! handler and other non-handler code.
//!
//! \note The use of this function (directly or indirectly via a peripheral
//! driver interrupt register function) moves the interrupt vector table from
//! flash to SRAM. Therefore, care must be taken when linking the application
//! to ensure that the SRAM vector table is located at the beginning of SRAM;
//! otherwise NVIC will not look in the correct portion of memory for the
//! vector table (it requires the vector table be on a 1 kB memory alignment).
//! Normally, the SRAM vector table is so placed via the use of linker scripts;
//! some tool chains, such as the evaluation version of RV-MDK, do not support
//! linker scripts and therefore will not produce a valid executable. See the
//! discussion of compile-time versus run-time interrupt handler registration
//! in the introduction to this chapter.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_register) || defined(BUILD_ALL) || defined(DOXYGEN)
void
IntRegister(unsigned long ulInterrupt, void (*pfnHandler)(void))
{
unsigned long ulIdx;
//
// Check the arguments.
//
ASSERT(ulInterrupt < NUM_INTERRUPTS);
//
// Make sure that the RAM vector table is correctly aligned.
//
ASSERT(((unsigned long)g_pfnRAMVectors & 0x000003ff) == 0);
//
// See if the RAM vector table has been initialized.
//
if(HWREG(NVIC_VTABLE) != (unsigned long)g_pfnRAMVectors)
{
//
// Copy the vector table from the beginning of FLASH to the RAM vector
// table.
//
for(ulIdx = 0; ulIdx < NUM_INTERRUPTS; ulIdx++)
{
g_pfnRAMVectors[ulIdx] = (void (*)(void))HWREG(ulIdx * 4);
}
//
// Point NVIC at the RAM vector table.
//
HWREG(NVIC_VTABLE) = (unsigned long)g_pfnRAMVectors;
}
//
// Save the interrupt handler.
//
g_pfnRAMVectors[ulInterrupt] = pfnHandler;
}
#endif
//*****************************************************************************
//
//! Unregisters the function to be called when an interrupt occurs.
//!
//! \param ulInterrupt specifies the interrupt in question.
//!
//! This function is used to indicate that no handler should be called when the
//! given interrupt is asserted to the processor. The interrupt source will be
//! automatically disabled (via IntDisable()) if necessary.
//!
//! \sa IntRegister() for important information about registering interrupt
//! handlers.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_unregister) || defined(BUILD_ALL) || defined(DOXYGEN)
void
IntUnregister(unsigned long ulInterrupt)
{
//
// Check the arguments.
//
ASSERT(ulInterrupt < NUM_INTERRUPTS);
//
// Reset the interrupt handler.
//
g_pfnRAMVectors[ulInterrupt] = IntDefaultHandler;
}
#endif
//*****************************************************************************
//
//! Sets the priority grouping of the interrupt controller.
//!
//! \param ulBits specifies the number of bits of preemptable priority.
//!
//! This function specifies the split between preemptable priority levels and
//! subpriority levels in the interrupt priority specification. The range of
//! the grouping values are dependent upon the hardware implementation; on
//! the Stellaris family it can range from 0 to 3.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_prioritygroupingset) || defined(BUILD_ALL) || \
defined(DOXYGEN)
void
IntPriorityGroupingSet(unsigned long ulBits)
{
//
// Check the arguments.
//
ASSERT(ulBits < NUM_PRIORITY_BITS);
//
// Set the priority grouping.
//
HWREG(NVIC_APINT) = NVIC_APINT_VECTKEY | g_pulPriority[ulBits];
}
#endif
//*****************************************************************************
//
//! Gets the priority grouping of the interrupt controller.
//!
//! This function returns the split between preemptable priority levels and
//! subpriority levels in the interrupt priority specification.
//!
//! \return The number of bits of preemptable priority.
//
//*****************************************************************************
#if defined(GROUP_prioritygroupingget) || defined(BUILD_ALL) || \
defined(DOXYGEN)
unsigned long
IntPriorityGroupingGet(void)
{
unsigned long ulLoop, ulValue;
//
// Read the priority grouping.
//
ulValue = HWREG(NVIC_APINT) & NVIC_APINT_PRIGROUP_M;
//
// Loop through the priority grouping values.
//
for(ulLoop = 0; ulLoop < 8; ulLoop++)
{
//
// Stop looping if this value matches.
//
if(ulValue == g_pulPriority[ulLoop])
{
break;
}
}
//
// Return the number of priority bits.
//
return(ulLoop);
}
#endif
//*****************************************************************************
//
//! Sets the priority of an interrupt.
//!
//! \param ulInterrupt specifies the interrupt in question.
//! \param ucPriority specifies the priority of the interrupt.
//!
//! This function is used to set the priority of an interrupt. When multiple
//! interrupts are asserted simultaneously, the ones with the highest priority
//! are processed before the lower priority interrupts. Smaller numbers
//! correspond to higher interrupt priorities; priority 0 is the highest
//! interrupt priority.
//!
//! The hardware priority mechanism will only look at the upper N bits of the
//! priority level (where N is 3 for the Stellaris family), so any
//! prioritization must be performed in those bits. The remaining bits can be
//! used to sub-prioritize the interrupt sources, and may be used by the
//! hardware priority mechanism on a future part. This arrangement allows
//! priorities to migrate to different NVIC implementations without changing
//! the gross prioritization of the interrupts.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_priorityset) || defined(BUILD_ALL) || defined(DOXYGEN)
void
IntPrioritySet(unsigned long ulInterrupt, unsigned char ucPriority)
{
unsigned long ulTemp;
//
// Check the arguments.
//
ASSERT((ulInterrupt >= 4) && (ulInterrupt < NUM_INTERRUPTS));
//
// Set the interrupt priority.
//
ulTemp = HWREG(g_pulRegs[ulInterrupt >> 2]);
ulTemp &= ~(0xFF << (8 * (ulInterrupt & 3)));
ulTemp |= ucPriority << (8 * (ulInterrupt & 3));
HWREG(g_pulRegs[ulInterrupt >> 2]) = ulTemp;
}
#endif
//*****************************************************************************
//
//! Gets the priority of an interrupt.
//!
//! \param ulInterrupt specifies the interrupt in question.
//!
//! This function gets the priority of an interrupt. See IntPrioritySet() for
//! a definition of the priority value.
//!
//! \return Returns the interrupt priority, or -1 if an invalid interrupt was
//! specified.
//
//*****************************************************************************
#if defined(GROUP_priorityget) || defined(BUILD_ALL) || defined(DOXYGEN)
long
IntPriorityGet(unsigned long ulInterrupt)
{
//
// Check the arguments.
//
ASSERT((ulInterrupt >= 4) && (ulInterrupt < NUM_INTERRUPTS));
//
// Return the interrupt priority.
//
return((HWREG(g_pulRegs[ulInterrupt >> 2]) >> (8 * (ulInterrupt & 3))) &
0xFF);
}
#endif
//*****************************************************************************
//
//! Enables an interrupt.
//!
//! \param ulInterrupt specifies the interrupt to be enabled.
//!
//! The specified interrupt is enabled in the interrupt controller. Other
//! enables for the interrupt (such as at the peripheral level) are unaffected
//! by this function.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_enable) || defined(BUILD_ALL) || defined(DOXYGEN)
void
IntEnable(unsigned long ulInterrupt)
{
//
// Check the arguments.
//
ASSERT(ulInterrupt < NUM_INTERRUPTS);
//
// Determine the interrupt to enable.
//
if(ulInterrupt == FAULT_MPU)
{
//
// Enable the MemManage interrupt.
//
HWREG(NVIC_SYS_HND_CTRL) |= NVIC_SYS_HND_CTRL_MEM;
}
else if(ulInterrupt == FAULT_BUS)
{
//
// Enable the bus fault interrupt.
//
HWREG(NVIC_SYS_HND_CTRL) |= NVIC_SYS_HND_CTRL_BUS;
}
else if(ulInterrupt == FAULT_USAGE)
{
//
// Enable the usage fault interrupt.
//
HWREG(NVIC_SYS_HND_CTRL) |= NVIC_SYS_HND_CTRL_USAGE;
}
else if(ulInterrupt == FAULT_SYSTICK)
{
//
// Enable the System Tick interrupt.
//
HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_INTEN;
}
else if(ulInterrupt >= INT_GPIOA)
{
//
// Enable the general interrupt.
//
HWREG(NVIC_EN0) = 1 << (ulInterrupt - INT_GPIOA);
}
}
#endif
//*****************************************************************************
//
//! Disables an interrupt.
//!
//! \param ulInterrupt specifies the interrupt to be disabled.
//!
//! The specified interrupt is disabled in the interrupt controller. Other
//! enables for the interrupt (such as at the peripheral level) are unaffected
//! by this function.
//!
//! \return None.
//
//*****************************************************************************
#if defined(GROUP_disable) || defined(BUILD_ALL) || defined(DOXYGEN)
void
IntDisable(unsigned long ulInterrupt)
{
//
// Check the arguments.
//
ASSERT(ulInterrupt < NUM_INTERRUPTS);
//
// Determine the interrupt to disable.
//
if(ulInterrupt == FAULT_MPU)
{
//
// Disable the MemManage interrupt.
//
HWREG(NVIC_SYS_HND_CTRL) &= ~(NVIC_SYS_HND_CTRL_MEM);
}
else if(ulInterrupt == FAULT_BUS)
{
//
// Disable the bus fault interrupt.
//
HWREG(NVIC_SYS_HND_CTRL) &= ~(NVIC_SYS_HND_CTRL_BUS);
}
else if(ulInterrupt == FAULT_USAGE)
{
//
// Disable the usage fault interrupt.
//
HWREG(NVIC_SYS_HND_CTRL) &= ~(NVIC_SYS_HND_CTRL_USAGE);
}
else if(ulInterrupt == FAULT_SYSTICK)
{
//
// Disable the System Tick interrupt.
//
HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_INTEN);
}
else if(ulInterrupt >= INT_GPIOA)
{
//
// Disable the general interrupt.
//
HWREG(NVIC_DIS0) = 1 << (ulInterrupt - INT_GPIOA);
}
}
#endif
//*****************************************************************************
//
// Close the Doxygen group.
//! @}
//
//*****************************************************************************