include/bsp/system-clocks.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSBSPsARMLPC176X_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_LPC176X_SYSTEM_CLOCKS_H
0037 #define LIBBSP_ARM_LPC176X_SYSTEM_CLOCKS_H
0038
0039 #include <bsp/lpc176x.h>
0040 #include <bsp/timer-defs.h>
0041
0042 #ifdef __cplusplus
0043 extern "C" {
0044 #endif /* __cplusplus */
0045
0046 /**
0047  * @defgroup lpc176x_clock System Clocks
0048  *
0049  * @ingroup RTEMSBSPsARMLPC176X
0050  *
0051  * @brief System clocks.
0052  *
0053  * @{
0054  */
0055
0056 /**
0057  * @brief Initializes the standard timer.
0058  *
0059  * This function uses Timer 1.
0060  */
0061 void lpc176x_timer_initialize( void );
0062
0063 /**
0064  * @brief Returns current standard timer value in CPU clocks.
0065  *
0066  * @return This function uses Timer 1.
0067  */
0068 static inline unsigned lpc176x_get_timer1( void )
0069 {
0070   return LPC176X_T1TC;
0071 }
0072
0073 /**
0074  * @brief Delay for @a us micro seconds.
0075  *
0076  * This function uses the standard timer and assumes that the CPU
0077  * frequency is in whole MHz numbers.  The delay value @a us will be
0078  * converted to CPU ticks and there is no protection against integer
0079  * overflows.
0080  *
0081  * This function uses Timer 1.
0082  */
0083 void lpc176x_micro_seconds_delay( unsigned us );
0084
0085 /**
0086  * @brief Returns the PLL output clock frequency in [Hz].
0087  *
0088  * @return Returns zero in case of an unexpected PLL input frequency.
0089  */
0090 unsigned lpc176x_pllclk( void );
0091
0092 /**
0093  * @brief Returns the CPU clock frequency in [Hz].
0094  *
0095  * @return Returns zero in case of an unexpected PLL input frequency.
0096  */
0097 unsigned lpc176x_cclk( void );
0098
0099 /** @} */
0100
0101 #ifdef __cplusplus
0102 }
0103 #endif /* __cplusplus */
0104
0105 #endif /* LIBBSP_ARM_LPC176X_SYSTEM_CLOCKS_H */