include/bsp/system-clocks.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSBSPsARMLPC24XX_clocks
0007  *
0008  * @brief System clocks.
0009  */
0010
0011 /*
0012  * Copyright (C) 2008, 2009 embedded brains GmbH & Co. KG
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #ifndef LIBBSP_ARM_LPC24XX_SYSTEM_CLOCKS_H
0037 #define LIBBSP_ARM_LPC24XX_SYSTEM_CLOCKS_H
0038
0039 #include <bsp/lpc24xx.h>
0040
0041 #ifdef __cplusplus
0042 extern "C" {
0043 #endif /* __cplusplus */
0044
0045 /**
0046  * @defgroup lpc24xx_clock System Clocks
0047  *
0048  * @ingroup RTEMSBSPsARMLPC24XX
0049  *
0050  * @brief System clocks.
0051  *
0052  * @{
0053  */
0054
0055 /**
0056  * @brief Initializes the standard timer.
0057  *
0058  * This function uses Timer 1.
0059  */
0060 void lpc24xx_timer_initialize(void);
0061
0062 /**
0063  * @brief Returns current standard timer value in CPU clocks.
0064  *
0065  * This function uses Timer 1.
0066  */
0067 static inline unsigned lpc24xx_timer(void)
0068 {
0069   return T1TC;
0070 }
0071
0072 /**
0073  * @brief Delay for @a us micro seconds.
0074  *
0075  * This function uses the standard timer and assumes that the CPU frequency is
0076  * in whole MHz numbers.  The delay value @a us will be converted to CPU ticks
0077  * and there is no protection against integer overflows.
0078  *
0079  * This function uses Timer 1.
0080  */
0081 void lpc24xx_micro_seconds_delay(unsigned us);
0082
0083 /**
0084  * @brief Returns the PLL output clock frequency in [Hz].
0085  *
0086  * Returns zero in case of an unexpected PLL input frequency.
0087  */
0088 unsigned lpc24xx_pllclk(void);
0089
0090 /**
0091  * @brief Returns the CPU clock frequency in [Hz].
0092  *
0093  * Returns zero in case of an unexpected PLL input frequency.
0094  */
0095 unsigned lpc24xx_cclk(void);
0096
0097 /** @} */
0098
0099 #ifdef __cplusplus
0100 }
0101 #endif /* __cplusplus */
0102
0103 #endif /* LIBBSP_ARM_LPC24XX_SYSTEM_CLOCKS_H */