Suga koubou
see: http://mbed.org/users/okini3939/notebook/low-power-lpc81x/
system_LPC8xx.c
- Committer:
- okini3939
- Date:
- 2013-06-07
- Revision:
- 1:f336c9774f7a
File content as of revision 1:f336c9774f7a:
// Updated - Code Red Technologies - 18 March 2013
//
// Defines in system_LPC8xx.c changed so that clock setup is
// done based on IRC rather than XTAL, so as to function with
// LPC800-MAX board as well as LPCXpresso812. SystemCoreClock
// thus now defaults to 12MHz
//
/******************************************************************************
* @file: system_LPC8xx.c
* @purpose: CMSIS Cortex-M0+ Device Peripheral Access Layer Source File
* for the NXP LPC8xx Device Series
* @version: V1.0
* @date: 16. Aug. 2012
*----------------------------------------------------------------------------
*
* Copyright (C) 2012 ARM Limited. All rights reserved.
*
* ARM Limited (ARM) is supplying this software for use with Cortex-M0+
* processor based microcontrollers. This file can be freely distributed
* within development tools that are supporting such ARM based processors.
*
* THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
* ARM SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
* CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
*
******************************************************************************/
#include <stdint.h>
#include "LPC8xx.h"
/*
//-------- <<< Use Configuration Wizard in Context Menu >>> ------------------
*/
/*--------------------- Clock Configuration ----------------------------------
//
// <e> Clock Configuration
// <h> System Oscillator Control Register (SYSOSCCTRL)
// <o1.0> BYPASS: System Oscillator Bypass Enable
// <i> If enabled then PLL input (sys_osc_clk) is fed
// <i> directly from XTALIN and XTALOUT pins.
// <o1.9> FREQRANGE: System Oscillator Frequency Range
// <i> Determines frequency range for Low-power oscillator.
// <0=> 1 - 20 MHz
// <1=> 15 - 25 MHz
// </h>
//
// <h> Watchdog Oscillator Control Register (WDTOSCCTRL)
// <o2.0..4> DIVSEL: Select Divider for Fclkana
// <i> wdt_osc_clk = Fclkana/ (2 ・ｽ (1 + DIVSEL))
// <0-31>
// <o2.5..8> FREQSEL: Select Watchdog Oscillator Analog Output Frequency (Fclkana)
// <0=> Undefined
// <1=> 0.5 MHz
// <2=> 0.8 MHz
// <3=> 1.1 MHz
// <4=> 1.4 MHz
// <5=> 1.6 MHz
// <6=> 1.8 MHz
// <7=> 2.0 MHz
// <8=> 2.2 MHz
// <9=> 2.4 MHz
// <10=> 2.6 MHz
// <11=> 2.7 MHz
// <12=> 2.9 MHz
// <13=> 3.1 MHz
// <14=> 3.2 MHz
// <15=> 3.4 MHz
// </h>
//
// <h> System PLL Control Register (SYSPLLCTRL)
// <i> F_clkout = M * F_clkin = F_CCO / (2 * P)
// <i> F_clkin must be in the range of 10 MHz to 25 MHz
// <i> F_CCO must be in the range of 156 MHz to 320 MHz
// <o3.0..4> MSEL: Feedback Divider Selection
// <i> M = MSEL + 1
// <0-31>
// <o3.5..6> PSEL: Post Divider Selection
// <0=> P = 1
// <1=> P = 2
// <2=> P = 4
// <3=> P = 8
// </h>
//
// <h> System PLL Clock Source Select Register (SYSPLLCLKSEL)
// <o4.0..1> SEL: System PLL Clock Source
// <0=> IRC Oscillator
// <1=> System Oscillator
// <2=> Reserved
// <3=> CLKIN pin
// </h>
//
// <h> Main Clock Source Select Register (MAINCLKSEL)
// <o5.0..1> SEL: Clock Source for Main Clock
// <0=> IRC Oscillator
// <1=> Input Clock to System PLL
// <2=> WDT Oscillator
// <3=> System PLL Clock Out
// </h>
//
// <h> System AHB Clock Divider Register (SYSAHBCLKDIV)
// <o6.0..7> DIV: System AHB Clock Divider
// <i> Divides main clock to provide system clock to core, memories, and peripherals.
// <i> 0 = is disabled
// <0-255>
// </h>
// </e>
*/
#define CLOCK_SETUP 0
#define SYSOSCCTRL_Val 0x00000000 // Reset: 0x000
#define WDTOSCCTRL_Val 0x00000000 // Reset: 0x000
#define SYSPLLCTRL_Val 0x00000041 // Reset: 0x000
#define SYSPLLCLKSEL_Val 0x00000000 // Reset: 0x000
#define MAINCLKSEL_Val 0x00000000 // Reset: 0x000
#define SYSAHBCLKDIV_Val 0x00000001 // Reset: 0x001
/*
//-------- <<< end of configuration section >>> ------------------------------
*/
/*----------------------------------------------------------------------------
Check the register settings
*----------------------------------------------------------------------------*/
#define CHECK_RANGE(val, min, max) ((val < min) || (val > max))
#define CHECK_RSVD(val, mask) (val & mask)
/* Clock Configuration -------------------------------------------------------*/
#if (CHECK_RSVD((SYSOSCCTRL_Val), ~0x00000003))
#error "SYSOSCCTRL: Invalid values of reserved bits!"
#endif
#if (CHECK_RSVD((WDTOSCCTRL_Val), ~0x000001FF))
#error "WDTOSCCTRL: Invalid values of reserved bits!"
#endif
#if (CHECK_RANGE((SYSPLLCLKSEL_Val), 0, 3))
#error "SYSPLLCLKSEL: Value out of range!"
#endif
#if (CHECK_RSVD((SYSPLLCTRL_Val), ~0x000001FF))
#error "SYSPLLCTRL: Invalid values of reserved bits!"
#endif
#if (CHECK_RSVD((MAINCLKSEL_Val), ~0x00000003))
#error "MAINCLKSEL: Invalid values of reserved bits!"
#endif
#if (CHECK_RANGE((SYSAHBCLKDIV_Val), 0, 255))
#error "SYSAHBCLKDIV: Value out of range!"
#endif
/*----------------------------------------------------------------------------
DEFINES
*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
Define clocks
*----------------------------------------------------------------------------*/
#define __XTAL (12000000UL) /* Oscillator frequency */
#define __SYS_OSC_CLK ( __XTAL) /* Main oscillator frequency */
#define __IRC_OSC_CLK (12000000UL) /* Internal RC oscillator frequency */
#define __CLKIN_CLK (12000000UL) /* CLKIN pin frequency */
#define __FREQSEL ((WDTOSCCTRL_Val >> 5) & 0x0F)
#define __DIVSEL (((WDTOSCCTRL_Val & 0x1F) << 1) + 2)
#if (CLOCK_SETUP) /* Clock Setup */
#if (__FREQSEL == 0)
#define __WDT_OSC_CLK ( 0) /* undefined */
#elif (__FREQSEL == 1)
#define __WDT_OSC_CLK ( 500000 / __DIVSEL)
#elif (__FREQSEL == 2)
#define __WDT_OSC_CLK ( 800000 / __DIVSEL)
#elif (__FREQSEL == 3)
#define __WDT_OSC_CLK (1100000 / __DIVSEL)
#elif (__FREQSEL == 4)
#define __WDT_OSC_CLK (1400000 / __DIVSEL)
#elif (__FREQSEL == 5)
#define __WDT_OSC_CLK (1600000 / __DIVSEL)
#elif (__FREQSEL == 6)
#define __WDT_OSC_CLK (1800000 / __DIVSEL)
#elif (__FREQSEL == 7)
#define __WDT_OSC_CLK (2000000 / __DIVSEL)
#elif (__FREQSEL == 8)
#define __WDT_OSC_CLK (2200000 / __DIVSEL)
#elif (__FREQSEL == 9)
#define __WDT_OSC_CLK (2400000 / __DIVSEL)
#elif (__FREQSEL == 10)
#define __WDT_OSC_CLK (2600000 / __DIVSEL)
#elif (__FREQSEL == 11)
#define __WDT_OSC_CLK (2700000 / __DIVSEL)
#elif (__FREQSEL == 12)
#define __WDT_OSC_CLK (2900000 / __DIVSEL)
#elif (__FREQSEL == 13)
#define __WDT_OSC_CLK (3100000 / __DIVSEL)
#elif (__FREQSEL == 14)
#define __WDT_OSC_CLK (3200000 / __DIVSEL)
#else
#define __WDT_OSC_CLK (3400000 / __DIVSEL)
#endif
/* sys_pllclkin calculation */
#if ((SYSPLLCLKSEL_Val & 0x03) == 0)
#define __SYS_PLLCLKIN (__IRC_OSC_CLK)
#elif ((SYSPLLCLKSEL_Val & 0x03) == 1)
#define __SYS_PLLCLKIN (__SYS_OSC_CLK)
#elif ((SYSPLLCLKSEL_Val & 0x03) == 3)
#define __SYS_PLLCLKIN (__CLKIN_CLK)
#else
#define __SYS_PLLCLKIN (0)
#endif
#define __SYS_PLLCLKOUT (__SYS_PLLCLKIN * ((SYSPLLCTRL_Val & 0x01F) + 1))
/* main clock calculation */
#if ((MAINCLKSEL_Val & 0x03) == 0)
#define __MAIN_CLOCK (__IRC_OSC_CLK)
#elif ((MAINCLKSEL_Val & 0x03) == 1)
#define __MAIN_CLOCK (__SYS_PLLCLKIN)
#elif ((MAINCLKSEL_Val & 0x03) == 2)
#if (__FREQSEL == 0)
#error "MAINCLKSEL: WDT Oscillator selected but FREQSEL is undefined!"
#else
#define __MAIN_CLOCK (__WDT_OSC_CLK)
#endif
#elif ((MAINCLKSEL_Val & 0x03) == 3)
#define __MAIN_CLOCK (__SYS_PLLCLKOUT)
#else
#define __MAIN_CLOCK (0)
#endif
#define __SYSTEM_CLOCK (__MAIN_CLOCK / SYSAHBCLKDIV_Val)
#else
#define __SYSTEM_CLOCK (__IRC_OSC_CLK)
#endif // CLOCK_SETUP
/*----------------------------------------------------------------------------
Clock Variable definitions
*----------------------------------------------------------------------------*/
uint32_t SystemCoreClock = __SYSTEM_CLOCK;/*!< System Clock Frequency (Core Clock)*/
/*----------------------------------------------------------------------------
Clock functions
*----------------------------------------------------------------------------*/
void SystemCoreClockUpdate (void) /* Get Core Clock Frequency */
{
uint32_t wdt_osc = 0;
/* Determine clock frequency according to clock register values */
switch ((LPC_SYSCON->WDTOSCCTRL >> 5) & 0x0F) {
case 0: wdt_osc = 0; break;
case 1: wdt_osc = 500000; break;
case 2: wdt_osc = 800000; break;
case 3: wdt_osc = 1100000; break;
case 4: wdt_osc = 1400000; break;
case 5: wdt_osc = 1600000; break;
case 6: wdt_osc = 1800000; break;
case 7: wdt_osc = 2000000; break;
case 8: wdt_osc = 2200000; break;
case 9: wdt_osc = 2400000; break;
case 10: wdt_osc = 2600000; break;
case 11: wdt_osc = 2700000; break;
case 12: wdt_osc = 2900000; break;
case 13: wdt_osc = 3100000; break;
case 14: wdt_osc = 3200000; break;
case 15: wdt_osc = 3400000; break;
}
wdt_osc /= ((LPC_SYSCON->WDTOSCCTRL & 0x1F) << 1) + 2;
switch (LPC_SYSCON->MAINCLKSEL & 0x03) {
case 0: /* Internal RC oscillator */
SystemCoreClock = __IRC_OSC_CLK;
break;
case 1: /* Input Clock to System PLL */
switch (LPC_SYSCON->SYSPLLCLKSEL & 0x03) {
case 0: /* Internal RC oscillator */
SystemCoreClock = __IRC_OSC_CLK;
break;
case 1: /* System oscillator */
SystemCoreClock = __SYS_OSC_CLK;
break;
case 2: /* Reserved */
SystemCoreClock = 0;
break;
case 3: /* CLKIN pin */
SystemCoreClock = __CLKIN_CLK;
break;
}
break;
case 2: /* WDT Oscillator */
SystemCoreClock = wdt_osc;
break;
case 3: /* System PLL Clock Out */
switch (LPC_SYSCON->SYSPLLCLKSEL & 0x03) {
case 0: /* Internal RC oscillator */
SystemCoreClock = __IRC_OSC_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
break;
case 1: /* System oscillator */
SystemCoreClock = __SYS_OSC_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
break;
case 2: /* Reserved */
SystemCoreClock = 0;
break;
case 3: /* CLKIN pin */
SystemCoreClock = __CLKIN_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
break;
}
break;
}
SystemCoreClock /= LPC_SYSCON->SYSAHBCLKDIV;
}
/**
* Initialize the system
*
* @param none
* @return none
*
* @brief Setup the microcontroller system.
* Initialize the System.
*/
void SystemInit (void) {
volatile uint32_t i;
/* System clock to the IOCON & the SWM need to be enabled or
most of the I/O related peripherals won't work. */
LPC_SYSCON->SYSAHBCLKCTRL |= ( (0x1 << 7) | (0x1 << 18) );
#if (CLOCK_SETUP) /* Clock Setup */
#if ((SYSPLLCLKSEL_Val & 0x03) == 1)
LPC_IOCON->PIO0_8 &= ~(0x3 << 3);
LPC_IOCON->PIO0_9 &= ~(0x3 << 3);
LPC_SWM->PINENABLE0 &= ~(0x3 << 4);
LPC_SYSCON->PDRUNCFG &= ~(0x1 << 5); /* Power-up System Osc */
LPC_SYSCON->SYSOSCCTRL = SYSOSCCTRL_Val;
for (i = 0; i < 200; i++) __NOP();
#endif
#if ((SYSPLLCLKSEL_Val & 0x03) == 3)
LPC_IOCON->PIO0_1 &= ~(0x3 << 3);
LPC_SWM->PINENABLE0 &= ~(0x1 << 7);
for (i = 0; i < 200; i++) __NOP();
#endif
LPC_SYSCON->SYSPLLCLKSEL = SYSPLLCLKSEL_Val; /* Select PLL Input */
LPC_SYSCON->SYSPLLCLKUEN = 0x01; /* Update Clock Source */
while (!(LPC_SYSCON->SYSPLLCLKUEN & 0x01)); /* Wait Until Updated */
#if ((MAINCLKSEL_Val & 0x03) == 3) /* Main Clock is PLL Out */
LPC_SYSCON->SYSPLLCTRL = SYSPLLCTRL_Val;
LPC_SYSCON->PDRUNCFG &= ~(0x1 << 7); /* Power-up SYSPLL */
while (!(LPC_SYSCON->SYSPLLSTAT & 0x01)); /* Wait Until PLL Locked */
#endif
#if (((MAINCLKSEL_Val & 0x03) == 2) )
LPC_SYSCON->WDTOSCCTRL = WDTOSCCTRL_Val;
LPC_SYSCON->PDRUNCFG &= ~(0x1 << 6); /* Power-up WDT Clock */
for (i = 0; i < 200; i++) __NOP();
#endif
LPC_SYSCON->MAINCLKSEL = MAINCLKSEL_Val; /* Select PLL Clock Output */
LPC_SYSCON->MAINCLKUEN = 0x01; /* Update MCLK Clock Source */
while (!(LPC_SYSCON->MAINCLKUEN & 0x01)); /* Wait Until Updated */
LPC_SYSCON->SYSAHBCLKDIV = SYSAHBCLKDIV_Val;
#endif
}