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EPD-nRF5/components/drivers_nrf/systick/nrf_drv_systick.h
2024-12-19 15:08:21 +08:00

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4.6 KiB
C

/**
* Copyright (c) 2016 - 2017, Nordic Semiconductor ASA
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form, except as embedded into a Nordic
* Semiconductor ASA integrated circuit in a product or a software update for
* such product, must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. Neither the name of Nordic Semiconductor ASA nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* 4. This software, with or without modification, must only be used with a
* Nordic Semiconductor ASA integrated circuit.
*
* 5. Any software provided in binary form under this license must not be reverse
* engineered, decompiled, modified and/or disassembled.
*
* THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef NRF_DRV_SYSTICK_H__
#define NRF_DRV_SYSTICK_H__
#include <stdint.h>
#include <stdbool.h>
/**
* @addtogroup nrf_systick SysTick HAL and driver
* @ingroup nrf_drivers
* @brief System Timer (SysTick) APIs
*
* The SysTick HAL provides basic APIs for accessing the registers of the system timer (SysTick).
* The SysTick driver provides APIs on a higher level.
*/
/**
* @defgroup nrf_drv_systick SysTick driver
* @{
* @ingroup nrf_systick
*
* This library configures SysTick as a free-running timer.
* This timer is used to generate delays and pool for timeouts.
* Only relatively short timeouts are supported.
* The SysTick works on 64MHz and is 24-bits wide.
* It means that it overflows around 4 times per second and around 250&nbsp;ms
* would be the highest supported time in the library.
* But it would be really hard to detect if overflow was generated without
* using interrupts. For safely we would limit the maximum delay range by half.
*/
/**
* @brief The value type that holds the SysTick state
*
* This variable is used to count the requested timeout.
* @sa nrf_drv_systick_get
*/
typedef struct {
uint32_t time; //!< Registered time value
}nrf_drv_systick_state_t;
/**
* @brief Configure and start the timer
*
* Function configures SysTick as a free-running timer without interrupt.
*/
void nrf_drv_systick_init(void);
/**
* @brief Get current SysTick state
*
* Function gets current state of the SysTick timer.
* It can be used to check time-out by @ref nrf_drv_systick_test.
*
* @param[out] p_state The pointer to the state variable to be filled
*/
void nrf_drv_systick_get(nrf_drv_systick_state_t * p_state);
/**
* @brief Test if specified time is up in relation to remembered state
*
* @param[in] p_state Remembered state set by @ref nrf_drv_systick_get
* @param[in] us Required time-out.
*
* @retval true If current time is higher than specified state plus given time-out.
* @retval false If current time is lower than specified state plus given time-out
*/
bool nrf_drv_systick_test(nrf_drv_systick_state_t const * p_state, uint32_t us);
/**
* @brief Blocking delay in CPU ticks
*
* @param[in] ticks Number of CPU ticks to delay.
*/
void nrf_drv_systick_delay_ticks(uint32_t ticks);
/**
* @brief Blocking delay in us
*
* @param[in] us Number of microseconds to delay.
*/
void nrf_drv_systick_delay_us(uint32_t us);
/**
* @brief Blocking delay in ms
*
* This delay function removes the limits of the highest possible delay value.
*
* @param[in] ms Number of milliseconds to delay.
*/
void nrf_drv_systick_delay_ms(uint32_t ms);
/** @} */
#endif /* NRF_DRV_SYSTICK_H__ */