RIOT/msba2-common/board_common_init.c

/******************************************************************************
Copyright 2008-2009, Freie Universitaet Berlin (FUB). All rights reserved.

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and Telematics group (http://cst.mi.fu-berlin.de).
-------------------------------------------------------------------------------
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/**
 * @ingroup msba2
 * @{
 */

/**
 * @file
 * @brief       MSB-A2 board initialization
 *
 * @author      Freie Universität Berlin, Computer Systems & Telematics, FeuerWhere project
 * @author      Heiko Will
 * @author      Kaspar Schleiser
 * @author      Michael Baar <baar@inf.fu-berlin.de>
 *
 * @note        $Id$
 */
#include <board.h>
#include <lpc23xx.h>
#include <VIC.h>
#include <cpu.h>
#include <config.h>
#include <string.h>
#include <flashrom.h>

#define PCRTC         BIT9
#define CL_CPU_DIV    4

/*---------------------------------------------------------------------------*/
/**
 * @brief   Enabling MAM and setting number of clocks used for Flash memory fetch
 * @internal
 */
static void
init_mam(void)
{
    MAMCR  = 0x0000;
    MAMTIM = 0x0003;
    MAMCR  = 0x0002;
}
/*---------------------------------------------------------------------------*/
static inline void
pllfeed(void)
{
    PLLFEED = 0xAA;
    PLLFEED = 0x55;
}
/*---------------------------------------------------------------------------*/
void init_clks1(void)
{
    // Disconnect PLL
    PLLCON &= ~0x0002;
    pllfeed();

    // Disable PLL
    PLLCON &= ~0x0001;
    pllfeed();

    SCS |= 0x20;                        // Enable main OSC
    while( !(SCS & 0x40) );             // Wait until main OSC is usable

    /* select main OSC, 16MHz, as the PLL clock source */
    CLKSRCSEL = 0x0001;

    // Setting Multiplier and Divider values
    PLLCFG = 0x0008;                    // M=9 N=1 Fcco = 288 MHz
    pllfeed();

    // Enabling the PLL */
    PLLCON = 0x0001;
    pllfeed();

    /* Set clock divider to 4 (value+1) */
    CCLKCFG = CL_CPU_DIV - 1;           // Fcpu = 72 MHz

#if USE_USB
    USBCLKCFG = USBCLKDivValue;     /* usbclk = 288 MHz/6 = 48 MHz */
#endif
}

void init_clks2(void){
    // Wait for the PLL to lock to set frequency
    while(!(PLLSTAT & BIT26));

    // Connect the PLL as the clock source
    PLLCON = 0x0003;
    pllfeed();

    /* Check connect bit status */
    while (!(PLLSTAT & BIT25));
}

void bl_init_clks(void)
{
    PCONP = PCRTC;          // switch off everything except RTC
    init_clks1();
    init_clks2();
    init_mam();
}