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/******************************************************************************
* The MIT License
*
* Copyright (c) 2010 Perry Hung.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*****************************************************************************/
/**
* @file nvic.c
* @brief Nested vector interrupt controller support.
*/
#include <libmaple/nvic.h>
#include <libmaple/scb.h>
#include <libmaple/stm32.h>
/**
* @brief Set interrupt priority for an interrupt line
*
* Note: The STM32 only implements 4 bits of priority, ignoring the
* lower 4 bits. This means there are only 16 levels of priority.
* Bits[3:0] read as zero and ignore writes.
*
* @param irqn device to set
* @param priority Priority to set, 0 being highest priority and 15
* being lowest.
*/
void nvic_irq_set_priority(nvic_irq_num irqn, uint8 priority) {
if (irqn < 0) {
/* This interrupt is in the system handler block */
SCB_BASE->SHP[((uint32)irqn & 0xF) - 4] = (priority & 0xF) << 4;
} else {
NVIC_BASE->IP[irqn] = (priority & 0xF) << 4;
}
}
/**
* @brief Initialize the NVIC, setting interrupts to a default priority.
*/
void nvic_init(uint32 address, uint32 offset) {
uint32 i;
nvic_set_vector_table(address, offset);
/*
* Lower priority level for all peripheral interrupts to lowest
* possible.
*/
for (i = 0; i < STM32_NR_INTERRUPTS; i++) {
nvic_irq_set_priority((nvic_irq_num)i, 0xF);
}
/* Lower systick interrupt priority to lowest level */
nvic_irq_set_priority(NVIC_SYSTICK, 0xF);
}
/**
* @brief Set the vector table base address.
*
* For stand-alone products, the vector table base address is normally
* the start of Flash (0x08000000).
*
* @param address Vector table base address.
* @param offset Offset from address. Some restrictions apply to the
* use of nonzero offsets; see the ARM Cortex M3
* Technical Reference Manual.
*/
void nvic_set_vector_table(uint32 address, uint32 offset) {
SCB_BASE->VTOR = address | (offset & 0x1FFFFF80);
}
/**
* @brief Force a system reset.
*
* Resets all major system components, excluding debug.
*/
void nvic_sys_reset() {
uint32 prigroup = SCB_BASE->AIRCR & SCB_AIRCR_PRIGROUP;
SCB_BASE->AIRCR = SCB_AIRCR_VECTKEY | SCB_AIRCR_SYSRESETREQ | prigroup;
asm volatile("dsb");
while (1)
;
}
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