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/* mbed Microcontroller Library
* Copyright (C) 2008-2009 ARM Limited. All rights reserved.
*
* ARM7 version of CMSIS-like functionality - not advised for use outside mbed!
*/
#include <stdint.h>
#include "LPC23xx.h"
#define CLOCK_SETUP 1
#define SCS_Val 0x00000020
#define CLKSRCSEL_Val 0x00000001
#define PLL0_SETUP 1
#define PLL0CFG_Val 0x00000013
#define CCLKCFG_Val 0x00000007
#define USBCLKCFG_Val 0x00000009
#define PCLKSEL0_Val 0x00000000
#define PCLKSEL1_Val 0x00000000
#define PCONP_Val 0x042887DE
#define CLKOUTCFG_Val 0x00000000
#define MAMCR_Val 0x00000001 // there is a bug in the MAM so it should never be fully enabled (only disabled or partially enabled)
#define MAMTIM_Val 0x00000004
/*----------------------------------------------------------------------------
DEFINES
*----------------------------------------------------------------------------*/
#define XTAL (12000000UL) /* Oscillator frequency */
#define OSC_CLK ( XTAL) /* Main oscillator frequency */
#define RTC_CLK ( 32000UL) /* RTC oscillator frequency */
#define IRC_OSC ( 4000000UL) /* Internal RC oscillator frequency */
/* F_cco0 = (2 * M * F_in) / N */
#define __M (((PLL0CFG_Val ) & 0x7FFF) + 1)
#define __N (((PLL0CFG_Val >> 16) & 0x00FF) + 1)
#define __FCCO(__F_IN) ((2 * __M * __F_IN) / __N)
#define __CCLK_DIV (((CCLKCFG_Val ) & 0x00FF) + 1)
/* Determine core clock frequency according to settings */
#if (PLL0_SETUP)
#if ((CLKSRCSEL_Val & 0x03) == 1)
#define __CORE_CLK (__FCCO(OSC_CLK) / __CCLK_DIV)
#elif ((CLKSRCSEL_Val & 0x03) == 2)
#define __CORE_CLK (__FCCO(RTC_CLK) / __CCLK_DIV)
#else
#define __CORE_CLK (__FCCO(IRC_OSC) / __CCLK_DIV)
#endif
#endif
/*----------------------------------------------------------------------------
Clock Variable definitions
*----------------------------------------------------------------------------*/
uint32_t SystemCoreClock = __CORE_CLK;/*!< System Clock Frequency (Core Clock)*/
/*----------------------------------------------------------------------------
Clock functions
*----------------------------------------------------------------------------*/
void SystemCoreClockUpdate (void) /* Get Core Clock Frequency */
{
/* Determine clock frequency according to clock register values */
if (((LPC_SC->PLL0STAT >> 24) & 3) == 3) { /* If PLL0 enabled and connected */
switch (LPC_SC->CLKSRCSEL & 0x03) {
case 0: /* Int. RC oscillator => PLL0 */
case 3: /* Reserved, default to Int. RC */
SystemCoreClock = (IRC_OSC *
(((2 * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
(((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1)) /
((LPC_SC->CCLKCFG & 0xFF)+ 1));
break;
case 1: /* Main oscillator => PLL0 */
SystemCoreClock = (OSC_CLK *
(((2 * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
(((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1)) /
((LPC_SC->CCLKCFG & 0xFF)+ 1));
break;
case 2: /* RTC oscillator => PLL0 */
SystemCoreClock = (RTC_CLK *
(((2 * ((LPC_SC->PLL0STAT & 0x7FFF) + 1))) /
(((LPC_SC->PLL0STAT >> 16) & 0xFF) + 1)) /
((LPC_SC->CCLKCFG & 0xFF)+ 1));
break;
}
} else {
switch (LPC_SC->CLKSRCSEL & 0x03) {
case 0: /* Int. RC oscillator => PLL0 */
case 3: /* Reserved, default to Int. RC */
SystemCoreClock = IRC_OSC / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
break;
case 1: /* Main oscillator => PLL0 */
SystemCoreClock = OSC_CLK / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
break;
case 2: /* RTC oscillator => PLL0 */
SystemCoreClock = RTC_CLK / ((LPC_SC->CCLKCFG & 0xFF)+ 1);
break;
}
}
}
/**
* Initialize the system
*
* @param none
* @return none
*
* @brief Setup the microcontroller system.
* Initialize the System and update the SystemFrequency variable.
*/
void SystemInit (void)
{
#if (CLOCK_SETUP) /* Clock Setup */
LPC_SC->SCS = SCS_Val;
if (SCS_Val & (1 << 5)) { /* If Main Oscillator is enabled */
while ((LPC_SC->SCS & (1 << 6)) == 0); /* Wait for Oscillator to be ready */
}
LPC_SC->CCLKCFG = CCLKCFG_Val; /* Setup Clock Divider */
#if (PLL0_SETUP)
LPC_SC->CLKSRCSEL = CLKSRCSEL_Val; /* Select Clock Source for PLL0 */
LPC_SC->PLL0CFG = PLL0CFG_Val;
LPC_SC->PLL0CON = 0x01; /* PLL0 Enable */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
while (!(LPC_SC->PLL0STAT & (1 << 26))); /* Wait for PLOCK0 */
LPC_SC->PLL0CON = 0x03; /* PLL0 Enable & Connect */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
#endif
LPC_SC->USBCLKCFG = USBCLKCFG_Val; /* Setup USB Clock Divider */
#endif
LPC_SC->PCLKSEL0 = PCLKSEL0_Val; /* Peripheral Clock Selection */
LPC_SC->PCLKSEL1 = PCLKSEL1_Val;
LPC_SC->PCONP = PCONP_Val; /* Power Control for Peripherals */
// Setup MAM
LPC_SC->MAMTIM = MAMTIM_Val;
LPC_SC->MAMCR = MAMCR_Val;
}
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