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Diffstat (limited to 'c/src/lib/libbsp/arm/atsam/libraries/libchip/source/rtt.c')
| -rw-r--r-- | c/src/lib/libbsp/arm/atsam/libraries/libchip/source/rtt.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/atsam/libraries/libchip/source/rtt.c b/c/src/lib/libbsp/arm/atsam/libraries/libchip/source/rtt.c new file mode 100644 index 0000000000..8c6ae89e78 --- /dev/null +++ b/c/src/lib/libbsp/arm/atsam/libraries/libchip/source/rtt.c @@ -0,0 +1,134 @@ +/* ---------------------------------------------------------------------------- */ +/* Atmel Microcontroller Software Support */ +/* SAM Software Package License */ +/* ---------------------------------------------------------------------------- */ +/* Copyright (c) 2015, Atmel Corporation */ +/* */ +/* All rights reserved. */ +/* */ +/* Redistribution and use in source and binary forms, with or without */ +/* modification, are permitted provided that the following condition is met: */ +/* */ +/* - Redistributions of source code must retain the above copyright notice, */ +/* this list of conditions and the disclaimer below. */ +/* */ +/* Atmel's name may not be used to endorse or promote products derived from */ +/* this software without specific prior written permission. */ +/* */ +/* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR */ +/* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */ +/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE */ +/* DISCLAIMED. IN NO EVENT SHALL ATMEL 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. */ +/* ---------------------------------------------------------------------------- */ + +/** \addtogroup rtt_module Working with RTT + * \ingroup peripherals_module + * The RTT driver provides the interface to configure and use the RTT + * peripheral. + * + * The Real-time Timer is used to count elapsed seconds.\n + * This timer is clocked by the 32kHz system clock divided by a programmable + * 16-bit value. To be accurate, it is better to use an + * external 32kHz crystal instead of the internal 32kHz RC.\n + * + * To count elapsed seconds, the user could follow these few steps: + * <ul> + * <li>Programming PTPRES in RTT_MR to feeding the timer with a 1Hz signal.</li> + * <li>Writing the bit RTTRST in RTT_MR to restart the timer with new settings. + * </li> + * </ul> + * + * An alarm can be set to happen on second by setting alarm value in RTT_AR. + * Alarm occurrence can be detected by polling or interrupt. + * + * For more accurate information, please look at the RTT section of the + * Datasheet. + * + * Related files :\n + * \ref rtt.c\n + * \ref rtt.h.\n + */ +/*@{*/ +/*@}*/ + +/** + * \file + * + * Implementation of Real Time Timer (RTT) controller. + * + */ + +/*---------------------------------------------------------------------------- + * Headers + *----------------------------------------------------------------------------*/ +#include "chip.h" + +#include <assert.h> + +/*---------------------------------------------------------------------------- + * Exported functions + *----------------------------------------------------------------------------*/ + +/** + * \brief Changes the prescaler value of the given RTT and restarts it. + * + * \note This function disables RTT interrupt sources. + * + * \param rtt Pointer to a Rtt instance. + * \param prescaler Prescaler value for the RTT. + */ +void RTT_SetPrescaler(Rtt *rtt, uint16_t prescaler) +{ + rtt->RTT_MR = (prescaler | RTT_MR_RTTRST); +} + +/** + * \brief Returns the current value of the RTT timer value. + * + * \param rtt Pointer to a Rtt instance. + */ +uint32_t RTT_GetTime(Rtt *rtt) +{ + return rtt->RTT_VR; +} + +/** + * \brief Enables the specified RTT interrupt sources. + * + * \param rtt Pointer to a Rtt instance. + * \param sources Bitmask of interrupts to enable. + */ +void RTT_EnableIT(Rtt *rtt, uint32_t sources) +{ + assert((sources & 0x0004FFFF) == 0); + rtt->RTT_MR |= sources; +} + +/** + * \brief Returns the status register value of the given RTT. + * + * \param rtt Pointer to an Rtt instance. + */ +uint32_t RTT_GetStatus(Rtt *rtt) +{ + return rtt->RTT_SR; +} + +/** + * \brief Configures the RTT to generate an alarm at the given time. + * + * \param pRtt Pointer to an Rtt instance. + * \param time Alarm time. + */ +void RTT_SetAlarm(Rtt *pRtt, uint32_t time) +{ + assert(time > 0); + + pRtt->RTT_AR = time - 1; +} |