Files
tinyUSB/hw/mcu/nxp/lpc_chip_13xx/src/sysinit_13xx.c
2018-12-03 16:38:29 +07:00

133 lines
4.8 KiB
C

/*
* @brief LPC13xx Chip specific SystemInit
*
* @note
* Copyright(C) NXP Semiconductors, 2013
* All rights reserved.
*
* @par
* Software that is described herein is for illustrative purposes only
* which provides customers with programming information regarding the
* LPC products. This software is supplied "AS IS" without any warranties of
* any kind, and NXP Semiconductors and its licensor disclaim any and
* all warranties, express or implied, including all implied warranties of
* merchantability, fitness for a particular purpose and non-infringement of
* intellectual property rights. NXP Semiconductors assumes no responsibility
* or liability for the use of the software, conveys no license or rights under any
* patent, copyright, mask work right, or any other intellectual property rights in
* or to any products. NXP Semiconductors reserves the right to make changes
* in the software without notification. NXP Semiconductors also makes no
* representation or warranty that such application will be suitable for the
* specified use without further testing or modification.
*
* @par
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, under NXP Semiconductors' and its
* licensor's relevant copyrights in the software, without fee, provided that it
* is used in conjunction with NXP Semiconductors microcontrollers. This
* copyright, permission, and disclaimer notice must appear in all copies of
* this code.
*/
#include "chip.h"
/*****************************************************************************
* Private types/enumerations/variables
****************************************************************************/
/*****************************************************************************
* Public types/enumerations/variables
****************************************************************************/
/*****************************************************************************
* Private functions
****************************************************************************/
/*****************************************************************************
* Public functions
****************************************************************************/
/* Setup system clocking */
void Chip_SetupXtalClocking(void)
{
volatile int i;
/* Powerup main oscillator */
Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_SYSOSC_PD);
/* Wait an estimated 200us for OSC to be stablized, no status
indication, dummy wait */
for (i = 0; i < 0x200; i++) {}
/* Set system PLL input to main oscillator */
Chip_Clock_SetSystemPLLSource(SYSCTL_PLLCLKSRC_SYSOSC);
/* Power down PLL to change the PLL divider ratio */
Chip_SYSCTL_PowerDown(SYSCTL_POWERDOWN_SYSPLL_PD);
/* Setup PLL for main oscillator rate (FCLKIN = 12MHz) * 6 = 72MHz
MSEL = 5 (this is pre-decremented), PSEL = 1 (for P = 2)
FCLKOUT = FCLKIN * (MSEL + 1) = 12MHz * 6 = 72MHz
FCCO = FCLKOUT * 2 * P = 72MHz * 2 * 2 = 288MHz (within FCCO range) */
Chip_Clock_SetupSystemPLL(5, 1);
/* Powerup system PLL */
Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_SYSPLL_PD);
/* Wait for PLL to lock */
while (!Chip_Clock_IsSystemPLLLocked()) {}
/* Set system clock divider to 1 */
Chip_Clock_SetSysClockDiv(1);
/* Setup FLASH access to 3 clocks (72MHz clock) */
Chip_FMC_SetFLASHAccess(FLASHTIM_72MHZ_CPU);
/* Set main clock source to the system PLL. This will drive 72MHz
for the main clock and 72MHz for the system clock */
Chip_Clock_SetMainClockSource(SYSCTL_MAINCLKSRC_PLLOUT);
}
/* Set up and initialize hardware prior to call to main */
void Chip_SetupIrcClocking(void)
{
/* IRC should be powered up */
Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_IRC_PD);
Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_IRCOUT_PD);
/* Set system PLL input to main oscillator */
Chip_Clock_SetSystemPLLSource(SYSCTL_PLLCLKSRC_IRC);
/* Power down PLL to change the PLL divider ratio */
Chip_SYSCTL_PowerDown(SYSCTL_POWERDOWN_SYSPLL_PD);
/* Setup PLL for main oscillator rate (FCLKIN = 12MHz) * 6 = 72MHz
MSEL = 5 (this is pre-decremented), PSEL = 1 (for P = 2)
FCLKOUT = FCLKIN * (MSEL + 1) = 12MHz * 6 = 72MHz
FCCO = FCLKOUT * 2 * P = 72MHz * 2 * 2 = 288MHz (within FCCO range) */
Chip_Clock_SetupSystemPLL(5, 1);
/* Powerup system PLL */
Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_SYSPLL_PD);
/* Wait for PLL to lock */
while (!Chip_Clock_IsSystemPLLLocked()) {}
/* Set system clock divider to 1 */
Chip_Clock_SetSysClockDiv(1);
/* Setup FLASH access to 3 clocks */
Chip_FMC_SetFLASHAccess(FLASHTIM_72MHZ_CPU);
/* Set main clock source to the system PLL. This will drive 48MHz
for the main clock and 48MHz for the system clock */
Chip_Clock_SetMainClockSource(SYSCTL_MAINCLKSRC_PLLOUT);
}
/* Set up and initialize hardware prior to call to main */
void Chip_SystemInit(void)
{
/* Initial internal clocking */
Chip_SetupIrcClocking();
}