MCUXpresso_LPC804/devices/LPC804/system_LPC804.c

116 lines
3.5 KiB
C

/*
** ###################################################################
** Processors: LPC804M101JDH20
** LPC804M101JDH24
** LPC804M101JHI33
** LPC804M111JDH24
** LPC804UK
**
** Compilers: GNU C Compiler
** IAR ANSI C/C++ Compiler for ARM
** Keil ARM C/C++ Compiler
** MCUXpresso Compiler
**
** Reference manual: LPC804 User manual Rev.1.0 24 Jan 2018
** Version: rev. 1.0, 2018-01-09
** Build: b201015
**
** Abstract:
** Provides a system configuration function and a global variable that
** contains the system frequency. It configures the device and initializes
** the oscillator (PLL) that is part of the microcontroller device.
**
** Copyright 2016 Freescale Semiconductor, Inc.
** Copyright 2016-2020 NXP
** All rights reserved.
**
** SPDX-License-Identifier: BSD-3-Clause
**
** http: www.nxp.com
** mail: support@nxp.com
**
** Revisions:
** - rev. 1.0 (2018-01-09)
** Initial version.
**
** ###################################################################
*/
/*!
* @file LPC804
* @version 1.0
* @date 2018-01-09
* @brief Device specific configuration file for LPC804 (implementation file)
*
* Provides a system configuration function and a global variable that contains
* the system frequency. It configures the device and initializes the oscillator
* (PLL) that is part of the microcontroller device.
*/
#include <stdint.h>
#include "fsl_device_registers.h"
/* ----------------------------------------------------------------------------
-- Core clock
---------------------------------------------------------------------------- */
uint32_t SystemCoreClock = DEFAULT_SYSTEM_CLOCK;
/* ----------------------------------------------------------------------------
-- SystemInit()
---------------------------------------------------------------------------- */
void SystemInit (void) {
#if defined(__MCUXPRESSO)
extern void(*const g_pfnVectors[]) (void);
SCB->VTOR = (uint32_t) &g_pfnVectors;
#else
extern void *__Vectors;
SCB->VTOR = (uint32_t) &__Vectors;
#endif
SystemCoreClock = DEFAULT_SYSTEM_CLOCK;
SystemInitHook();
}
/* ----------------------------------------------------------------------------
-- SystemCoreClockUpdate()
---------------------------------------------------------------------------- */
void SystemCoreClockUpdate (void) {
switch (SYSCON->MAINCLKSEL & SYSCON_MAINCLKSEL_SEL_MASK)
{
case 0U: /* Free running oscillator (FRO / 2) */
SystemCoreClock = (g_Fro_Osc_Freq >> 1U);
break;
case 1U: /* System oscillator */
SystemCoreClock = CLK_OSC_IN;
break;
case 2U: /* lower power oscillator */
SystemCoreClock = CLK_OSC_LP;
break;
case 3U: /* Free running oscillator ((FRO / 2) / 2) */
SystemCoreClock = (g_Fro_Osc_Freq >> 2U);
break;
default:
SystemCoreClock = 0U;
break;
}
SystemCoreClock /= SYSCON->SYSAHBCLKDIV;
}
/* ----------------------------------------------------------------------------
-- SystemInitHook()
---------------------------------------------------------------------------- */
__attribute__ ((weak)) void SystemInitHook (void) {
/* Void implementation of the weak function. */
}