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2.2.1
Standard C library for AVR-GCC
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include
avr
interrupt.h
Go to the documentation of this file.
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/* Copyright (c) 2002,2005,2007 Marek Michalkiewicz
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Copyright (c) 2007, Dean Camera
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All rights reserved.
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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 are met:
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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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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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distribution.
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* Neither the name of the copyright holders nor the names of
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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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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE. */
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/* $Id$ */
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#ifndef _AVR_INTERRUPT_H_
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#define _AVR_INTERRUPT_H_
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#include <
avr/io.h
>
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#if !defined(__DOXYGEN__) && !defined(__STRINGIFY)
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/* Auxiliary macro for ISR_ALIAS(). */
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#define __STRINGIFY(x) #x
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#endif
/* !defined(__DOXYGEN__) */
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/** \file */
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/**@{*/
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/** \name Global manipulation of the interrupt flag
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The global interrupt flag is maintained in the I bit of the status
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register (SREG).
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Handling interrupts frequently requires attention regarding atomic
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access to objects that could be altered by code running within an
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interrupt context, see <util/atomic.h>.
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Frequently, interrupts are being disabled for periods of time in
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order to perform certain operations without being disturbed; see
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\ref optim_code_reorder for things to be taken into account with
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respect to compiler optimizations.
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*/
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/** \def sei()
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\ingroup avr_interrupts
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Enables interrupts by setting the global interrupt mask. This function
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actually compiles into a single line of assembly, so there is no function
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call overhead. However, the macro also implies a <i>memory barrier</i>
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which can cause additional loss of optimization.
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In order to implement atomic access to multi-byte objects,
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consider using the macros from <util/atomic.h>, rather than
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implementing them manually with cli() and sei().
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*/
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# define sei() __asm__ __volatile__ ("sei" ::: "memory")
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/** \def cli()
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\ingroup avr_interrupts
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Disables all interrupts by clearing the global interrupt mask. This function
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actually compiles into a single line of assembly, so there is no function
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call overhead. However, the macro also implies a <i>memory barrier</i>
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which can cause additional loss of optimization.
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In order to implement atomic access to multi-byte objects,
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consider using the macros from <util/atomic.h>, rather than
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implementing them manually with cli() and sei().
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*/
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# define cli() __asm__ __volatile__ ("cli" ::: "memory")
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/** \name Macros for writing interrupt handler functions */
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#if defined(__DOXYGEN__)
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/** \def ISR(vector [, attributes])
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\ingroup avr_interrupts
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Introduces an interrupt handler function (interrupt service
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routine) that runs with global interrupts initially disabled
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by default with no attributes specified.
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The attributes are optional and alter the behaviour and resultant
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generated code of the interrupt routine. Multiple attributes may
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be used for a single function, with a space seperating each
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attribute.
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Valid attributes are #ISR_BLOCK, #ISR_NOBLOCK, #ISR_NAKED,
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#ISR_FLATTEN, #ISR_NOICF, #ISR_NOGCCISR and ISR_ALIASOF(vect).
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\c vector must be one of the interrupt vector names that are
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valid for the particular MCU type.
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*/
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# define ISR(vector, [attributes])
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#else
/* real code */
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#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 1) || (__GNUC__ > 4)
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# define __INTR_ATTRS __used__, __externally_visible__
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#else
/* GCC < 4.1 */
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# define __INTR_ATTRS __used__
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#endif
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#ifdef __cplusplus
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# define ISR(vector, ...) \
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extern "C" void vector (void) __attribute__ ((__signal__,__INTR_ATTRS)) __VA_ARGS__; \
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void vector (void)
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#else
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# define ISR(vector, ...) \
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void vector (void) __attribute__ ((__signal__,__INTR_ATTRS)) __VA_ARGS__; \
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void vector (void)
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#endif
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#endif
/* DOXYGEN */
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#if defined(__DOXYGEN__)
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/** \def SIGNAL(vector)
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\ingroup avr_interrupts
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Introduces an interrupt handler function that runs with global interrupts
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initially disabled.
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This is the same as the ISR macro without optional attributes.
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\deprecated Do not use SIGNAL() in new code. Use ISR() instead.
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*/
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# define SIGNAL(vector)
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#else
/* real code */
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#ifdef __cplusplus
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# define SIGNAL(vector) \
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extern "C" void vector(void) __attribute__ ((__signal__, __INTR_ATTRS)); \
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void vector (void)
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#else
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# define SIGNAL(vector) \
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void vector (void) __attribute__ ((__signal__, __INTR_ATTRS)); \
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void vector (void)
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#endif
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#endif
/* DOXYGEN */
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#if defined(__DOXYGEN__)
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/** \def EMPTY_INTERRUPT(vector)
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\ingroup avr_interrupts
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Defines an empty interrupt handler function. This will not generate
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any prolog or epilog code and will only return from the #ISR. Do not
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define a function body as this will define it for you.
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Example:
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\code EMPTY_INTERRUPT(ADC_vect);\endcode */
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# define EMPTY_INTERRUPT(vector)
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#else
/* real code */
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#ifdef __cplusplus
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# define EMPTY_INTERRUPT(vector) \
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extern "C" void vector(void) __attribute__ ((__signal__,__naked__,__INTR_ATTRS)); \
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void vector (void) { __asm__ __volatile__ ("reti" ::: "memory"); }
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#else
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# define EMPTY_INTERRUPT(vector) \
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void vector (void) __attribute__ ((__signal__,__naked__,__INTR_ATTRS)); \
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void vector (void) { __asm__ __volatile__ ("reti" ::: "memory"); }
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#endif
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#endif
/* DOXYGEN */
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#if defined(__DOXYGEN__)
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/** \def ISR_ALIAS(vector, target_vector)
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\ingroup avr_interrupts
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Aliases a given vector to another one in the same manner as the
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ISR_ALIASOF attribute for the ISR() macro. Unlike the ISR_ALIASOF
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attribute macro however, this is compatible for all versions of
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GCC rather than just GCC version 4.2 onwards.
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\note This macro creates a trampoline function for the aliased
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macro. This will result in a two cycle penalty for the aliased
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vector compared to the ISR the vector is aliased to, due to the
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JMP/RJMP opcode used.
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\deprecated
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For new code, the use of ISR(..., ISR_ALIASOF(...)) is
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recommended.
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Example:
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\code
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ISR(INT0_vect)
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{
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PORTB = 42;
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}
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ISR_ALIAS(INT1_vect, INT0_vect);
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\endcode
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*/
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# define ISR_ALIAS(vector, target_vector)
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#else
/* real code */
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#ifdef __cplusplus
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# define ISR_ALIAS(vector, tgt) extern "C" void vector (void) \
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__attribute__((__signal__, __naked__, __INTR_ATTRS)); \
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void vector (void) { __asm__ __volatile__ ("%~jmp " __STRINGIFY(tgt) ::); }
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#else
/* !__cplusplus */
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# define ISR_ALIAS(vector, tgt) void vector (void) \
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__attribute__((__signal__, __naked__, __INTR_ATTRS)); \
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void vector (void) { __asm__ __volatile__ ("%~jmp " __STRINGIFY(tgt) ::); }
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#endif
/* __cplusplus */
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#endif
/* DOXYGEN */
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/** \def reti()
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\ingroup avr_interrupts
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Returns from an interrupt routine, enabling global interrupts. This should
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be the last command executed before leaving an #ISR defined with the
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#ISR_NAKED attribute.
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This macro actually compiles into a single line of assembly, so there is
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no function call overhead.
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\note According to the GCC documentation, the only code supported in
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naked functions is \ref inline_asm "inline assembly".
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*/
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# define reti() __asm__ __volatile__ ("reti" ::: "memory")
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#if defined(__DOXYGEN__)
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/** \def BADISR_vect
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\ingroup avr_interrupts
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\code #include <avr/interrupt.h> \endcode
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This is a vector which is aliased to __vector_default, the vector
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executed when an IRQ fires with no accompanying ISR handler. This
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may be used along with the ISR() macro to create a catch-all for
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undefined but used ISRs for debugging purposes.
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*/
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# define BADISR_vect
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#else
/* !DOXYGEN */
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# define BADISR_vect __vector_default
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#endif
/* DOXYGEN */
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/** \name ISR attributes */
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#if defined(__DOXYGEN__)
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/** \def ISR_BLOCK
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\ingroup avr_interrupts
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Identical to an ISR with no attributes specified. Global
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interrupts are initially disabled by the AVR hardware when
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entering the ISR, without the compiler modifying this state.
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Use this attribute in the attributes parameter of the #ISR macro.
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*/
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# define ISR_BLOCK
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/** \def ISR_NOBLOCK
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\ingroup avr_interrupts
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ISR runs with global interrupts initially enabled. The interrupt
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enable flag is activated by the compiler as early as possible
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within the ISR to ensure minimal processing delay for nested
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interrupts.
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This may be used to create nested ISRs, however care should be
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taken to avoid stack overflows, or to avoid infinitely entering
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the ISR for those cases where the AVR hardware does not clear the
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respective interrupt flag before entering the ISR.
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Use this attribute in the attributes parameter of the #ISR macro.
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*/
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# define ISR_NOBLOCK
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/** \def ISR_NAKED
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\ingroup avr_interrupts
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ISR is created with no prologue or epilogue code. The user code is
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responsible for preservation of the machine state including the
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SREG register, as well as placing a reti() at the end of the
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interrupt routine.
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Use this attribute in the attributes parameter of the #ISR macro.
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\note According to GCC documentation, the only code supported in
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naked functions is \ref inline_asm "inline assembly".
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*/
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# define ISR_NAKED
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/** \def ISR_FLATTEN
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\ingroup avr_interrupts
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The compiler will try to inline all called function into the ISR.
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This has an effect with GCC 4.6 and newer only.
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Use this attribute in the attributes parameter of the #ISR macro.
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*/
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# define ISR_FLATTEN
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/** \def ISR_NOICF
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\ingroup avr_interrupts
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Avoid identical-code-folding optimization against this ISR.
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This has an effect with GCC 5 and newer only.
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Use this attribute in the attributes parameter of the #ISR macro.
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*/
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# define ISR_NOICF
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/** \def ISR_NOGCCISR
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\ingroup avr_interrupts
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Do not generate
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<a href="https://sourceware.org/binutils/docs/as/AVR-Pseudo-Instructions.html">\c __gcc_isr pseudo instructions</a>
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for this ISR.
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This has an effect with
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<a href="https://gcc.gnu.org/gcc-8/changes.html#avr">GCC 8</a>
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and newer only.
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Use this attribute in the attributes parameter of the #ISR macro.
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*/
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# define ISR_NOGCCISR
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/** \def ISR_ALIASOF(target_vector)
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\ingroup avr_interrupts
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The ISR is linked to another ISR, specified by the vect parameter.
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This is compatible with GCC 4.2 and greater only.
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Use this attribute in the attributes parameter of the #ISR macro.
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Example:
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\code
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ISR (INT0_vect)
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{
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PORTB = 42;
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}
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ISR (INT1_vect, ISR_ALIASOF (INT0_vect));
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\endcode
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*/
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# define ISR_ALIASOF(target_vector)
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#else
/* !DOXYGEN */
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# define ISR_BLOCK
/* empty */
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/* FIXME: This won't work with older versions of avr-gcc as ISR_NOBLOCK
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will use `signal' and `interrupt' at the same time. */
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# define ISR_NOBLOCK __attribute__((__interrupt__))
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# define ISR_NAKED __attribute__((__naked__))
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#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || (__GNUC__ >= 5)
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# define ISR_FLATTEN __attribute__((__flatten__))
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#else
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# define ISR_FLATTEN
/* empty */
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#endif
/* has flatten (GCC 4.6+) */
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#if defined (__has_attribute)
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#if __has_attribute (__no_icf__)
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# define ISR_NOICF __attribute__((__no_icf__))
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#else
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# define ISR_NOICF
/* empty */
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#endif
/* has no_icf */
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#if __has_attribute (__no_gccisr__)
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# define ISR_NOGCCISR __attribute__((__no_gccisr__))
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#else
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# define ISR_NOGCCISR
/* empty */
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#endif
/* has no_gccisr */
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#endif
/* has __has_attribute (GCC 5+) */
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# define ISR_ALIASOF(v) __attribute__((__alias__(__STRINGIFY(v))))
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#endif
/* DOXYGEN */
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/**@}*/
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#endif
io.h
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