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/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
* Copyright (C) 2012 Fergus Noble <fergusnoble@gmail.com>
* Copyright (C) 2012 Benjamin Vernoux <titanmkd@gmail.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
/** @defgroup CM3_nvic_file NVIC
@ingroup CM3_files
@brief <b>libopencm3 Cortex Nested Vectored Interrupt Controller</b>
@version 1.0.0
@author @htmlonly &copy; @endhtmlonly 2010 Thomas Otto <tommi@viadmin.org>
@author @htmlonly &copy; @endhtmlonly 2012 Fergus Noble <fergusnoble@gmail.com>
@date 18 August 2012
Cortex processors provide 14 cortex-defined interrupts (NMI, usage faults,
systicks etc.) and varying numbers of implementation defined interrupts
(typically peripherial interrupts and DMA).
@see Cortex-M3 Devices Generic User Guide
@see STM32F10xxx Cortex-M3 programming manual
LGPL License Terms @ref lgpl_license
*/
/**@{*/
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/cm3/scs.h>
/*---------------------------------------------------------------------------*/
/** @brief NVIC Enable Interrupt
Enables a user interrupt.
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
*/
void nvic_enable_irq(uint8_t irqn)
{
NVIC_ISER(irqn / 32) = (1 << (irqn % 32));
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Disable Interrupt
Disables a user interrupt.
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
*/
void nvic_disable_irq(uint8_t irqn)
{
NVIC_ICER(irqn / 32) = (1 << (irqn % 32));
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Return Pending Interrupt
True if the interrupt has occurred and is waiting for service.
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
@return Boolean. Interrupt pending.
*/
uint8_t nvic_get_pending_irq(uint8_t irqn)
{
return NVIC_ISPR(irqn / 32) & (1 << (irqn % 32)) ? 1 : 0;
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Set Pending Interrupt
Force a user interrupt to a pending state. This has no effect if the interrupt
is already pending.
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
*/
void nvic_set_pending_irq(uint8_t irqn)
{
NVIC_ISPR(irqn / 32) = (1 << (irqn % 32));
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Clear Pending Interrupt
Force remove a user interrupt from a pending state. This has no effect if the
interrupt is actively being serviced.
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
*/
void nvic_clear_pending_irq(uint8_t irqn)
{
NVIC_ICPR(irqn / 32) = (1 << (irqn % 32));
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Return Active Interrupt
Interrupt has occurred and is currently being serviced.
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
@return Boolean. Interrupt active.
*/
uint8_t nvic_get_active_irq(uint8_t irqn)
{
return NVIC_IABR(irqn / 32) & (1 << (irqn % 32)) ? 1 : 0;
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Return Enabled Interrupt
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
@return Boolean. Interrupt enabled.
*/
uint8_t nvic_get_irq_enabled(uint8_t irqn)
{
return NVIC_ISER(irqn / 32) & (1 << (irqn % 32)) ? 1 : 0;
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Set Interrupt Priority
There are 16 priority levels only, given by the upper four bits of the priority
byte, as required by ARM standards. The priority levels are interpreted
according to the pre-emptive priority grouping set in the SCB Application
Interrupt and Reset Control Register (SCB_AIRCR), as done in @ref
scb_set_priority_grouping.
@param[in] irqn Unsigned int8. Interrupt number @ref nvic_stm32f1_userint
@param[in] priority Unsigned int8. Interrupt priority (0 ... 255 in steps of 16)
*/
void nvic_set_priority(uint8_t irqn, uint8_t priority)
{
/* code from lpc43xx/nvic.c -- this is quite a hack and alludes to the
* negative interrupt numbers assigned to the system interrupts. better
* handling would mean signed integers. */
if (irqn >= NVIC_IRQ_COUNT) {
/* Cortex-M system interrupts */
SCS_SHPR((irqn & 0xF) - 4) = priority;
} else {
/* Device specific interrupts */
NVIC_IPR(irqn) = priority;
}
}
/*---------------------------------------------------------------------------*/
/** @brief NVIC Software Trigger Interrupt
Generate an interrupt from software. This has no effect for unprivileged access
unless the privilege level has been elevated through the System Control
Registers.
@param[in] irqn Unsigned int16. Interrupt number (0 ... 239)
*/
void nvic_generate_software_interrupt(uint16_t irqn)
{
if (irqn <= 239) {
NVIC_STIR |= irqn;
}
}
/**@}*/