RIOT/msb-430-common/board_init.c

#include "cpu.h"
#include "board.h"
#include "kernel_internal.h"
#include "msp430.h"
#include "debug.h"

static volatile uint32_t __msp430_cpu_speed = MSP430_INITIAL_CPU_SPEED;

/*---------------------------------------------------------------------------*/
static uint8_t calc_umctl(uint16_t br)
{
    // from TI slaa049
    register uint8_t CMOD = 256 * br - 256 * (br + 1) / 2;
    register uint8_t c = 0;
    register int i = 0;
    register uint8_t a = CMOD;
    a <<= 1;

    do {
        if (a & 0x80) {		// Overflow to integer?
            a = a - 128 + CMOD;	// Yes, subtract 1.000000
            c |= 0x80;
        }
        else {
            a += CMOD;			// No, add fraction
        }

        if (i == 7) {
            return c;
        }

        i++;
        c >>= 1;
    }
    while (1);
}

static void msb_ports_init(void)
{
    // Port 1: Free port, for energy saving all outputs are set to zero.
    P1SEL = 0x00;	// Port1 Zweitfunktion
    P1OUT = 0x00;	// Port1 Ausgangsregister: 00000000 = 0x00
    P1DIR = 0xFF;	// Port1 Direction: 11111111 = 0xFF

    P2SEL = 0x20;	// Port2 Zweitfunktion
    P2OUT = 0x00;	// Port2 Ausgangsregister: 00000000 = 0x00
    P2DIR = 0x1C;	// Port2 Direction: 00011010 = 0x1C
    //   0 - P2.0 [IN ] -
    //   0 - P2.1 [OUT] -
    //   1 - P2.2 [IN ] -
    //   1 - P2.3 [OUT] -
    //   1 - P2.4 [OUT] -
    //   0 - P2.5 [IN ] -
    //   0 - P2.6 [IN ] - SD-KARTE Protect
    //   0 - P2.7 [IN ] - SD-KARTE Detect

    P3SEL = 0xC0;	// Port3 Zweitfunktion
    P3OUT = 0x09;	// Port3 Ausgangsregister: 00001001 = 0x09
    P3DIR = 0x2B;	// Port3 Direction
    //   1 - P3.0
    //   1 - P3.1
    //   0 - P3.2
    //   1 - P3.3
    //   0 - P3.4 [IN ] - SHT 11 DATA (OUT/IN)
    //   1 - P3.5 [OUT] - SHT 11 CLK
    //   0 - P3.6 [2-Funktion] - RS232_RxD
    //   0 - P3.7 [2-Funktion] - RS232_TxD

    // Port 4: Free port, for energy saving all outputs are set to zero.
    P4SEL = 0x00;	// Port4 Zweitfunktion
    P4OUT = 0x00;	// Port4 Ausgangsregister: 00000000 = 0x00
    P4DIR = 0xFF;	// Port4 Direction: 11111111 = 0xFF
    //   1 - P4.0 [OUT] - unused
    //   1 - P4.1 [OUT] - unused
    //   1 - P4.2 [OUT] - unused
    //   1 - P4.3 [OUT] - unused
    //   1 - P4.4 [OUT] - unused
    //   1 - P4.5 [OUT] - unused
    //   1 - P4.6 [OUT] - unused
    //   1 - P4.7 [OUT] - unused

    P5SEL = 0x00;	// Port5 Zweitfunktion: 00000000 = 0x00
    P5OUT = 0x80;	// Port5 Ausgangsregister: 00001001 = 0x09
    P5DIR = 0xFF;	// Port5 Direction: 11111011 = 0xFB
    //   1 - P5.0 [OUT] - SD-KARTE /CS
    //   1 - P5.1 [OUT] - SD-KARTE DI
    //   0 - P5.2 [IN ] - SD-KARTE DO
    //   1 - P5.3 [OUT] - SD-KARTE DCLK
    //   1 - P5.4 [OUT] - MMA GS1
    //   1 - P5.5 [OUT] - MMA GS2
    //   1 - P5.6 [OUT] - MMA /SLEEP
    //   1 - P5.7 [OUT] - LED_ROT 0-an, 1-aus

    P6SEL = 0x00;	// Port6 Zweitfunktion = 0x07
    P6OUT = 0x00;	// Port6 Ausgangsregister: 00000000 = 0x00
    P6DIR = 0xFF;	// Port6 Direction: 11111000 = 0xF8
    //   0 - P6.0 [AD-IN] - MMA X-Achse
    //   0 - P6.1 [AD-IN] - MMA Y-Achse
    //   0 - P6.2 [AD-IN] - MMA Z-Achse
    //   1 - P6.3 [OUT] - unused
    //   1 - P6.4 [OUT] - unused
    //   1 - P6.5 [OUT] - unused
    //   1 - P6.6 [OUT] - unused
    //   1 - P6.7 [OUT] - unused
}

void msp430_set_cpu_speed(uint32_t speed)
{
    dint();
    __msp430_cpu_speed = speed;
    msp430_init_dco();
    uint16_t br;
    UCTL1 = SWRST | CHAR;		// 8-bit character
    UTCTL1 |= SSEL1 | URXSE;	// UCLK = MCLK
    // activate
    U1ME |= UTXE1 | URXE1;		// Enable USART1 TXD/RXD
    br = (uint16_t)(__msp430_cpu_speed / 115200uL);
    UBR01  = br;				// set baudrate
    UBR11  = br >> 8;
    UMCTL1 = calc_umctl(br);	// set modulation

    UCTL1 &= ~SWRST;
    //clock_init();
    eint();
}

/*---------------------------------------------------------------------------*/
void
msp430_init_dco()
{
#if MSP430_HAS_EXTERNAL_CRYSTAL
    /*------------------ use external oszillator -----------------------*/
    uint16_t i;

    // Stop watchdog
    WDTCTL = WDTPW + WDTHOLD;

    //Init crystal for mclk
    //XT2 = HF XTAL
    BCSCTL1 = RSEL2;

    // Wait for xtal to stabilize
    do {
        IFG1 &= ~OFIFG;				// Clear oscillator fault flag

        for (i = 0xFF; i > 0; i--); // Time for flag to set
    }
    while ((IFG1 & OFIFG) != 0);	// Oscillator fault flag still set?

    BCSCTL2 = SELM_2 + SELS;		// MCLK und SMCLK = XT2 (safe)
#else
    /* Thdeltais code taken from the FU Berlin sources and reformatted. */
    int delta = __msp430_cpu_speed >> 12;
    //#define DELTA    600

    unsigned int compare, oldcapture = 0;
    unsigned int i;


    BCSCTL1 = 0xa4; /* ACLK is devided by 4. RSEL=6 no division for MCLK
		     and SSMCLK. XT2 is off. */

    // Init FLL to desired frequency using the 32762Hz crystal
#if MSP430_HAS_DCOR
    BCSCTL2 = 0x01;
#else
    BCSCTL2 = 0x00;
#endif

    WDTCTL = WDTPW + WDTHOLD;             /* Stop WDT */
    BCSCTL1 |= DIVA1 + DIVA0;             /* ACLK = LFXT1CLK/8 */

    for (i = 0xffff; i > 0; i--);         /* Delay for XTAL to settle */

    CCTL2 = CCIS0 + CM0 + CAP;            // Define CCR2, CAP, ACLK
    TACTL = TASSEL1 + TACLR + MC1;        // SMCLK, continous mode


    while (1) {

        while ((CCTL2 & CCIFG) != CCIFG);   /* Wait until capture occured! */

        CCTL2 &= ~CCIFG;                    /* Capture occured, clear flag */
        compare = CCR2;                     /* Get current captured SMCLK */
        compare = compare - oldcapture;     /* SMCLK difference */
        oldcapture = CCR2;                  /* Save current captured SMCLK */

        if (delta == compare) {
            break;                            /* if equal, leave "while(1)" */
        }
        else if (delta < compare) {         /* DCO is too fast, slow it down */
            DCOCTL--;

            if (DCOCTL == 0xFF) {             /* Did DCO role under? */
                BCSCTL1--;
            }
        }
        else {                              /* -> Select next lower RSEL */
            DCOCTL++;

            if (DCOCTL == 0x00) {             /* Did DCO role over? */
                BCSCTL1++;
            }

            /* -> Select next higher RSEL  */
        }
    }

    CCTL2 = 0;                            /* Stop CCR2 function */
    TACTL = 0;                            /* Stop Timer_A */

    BCSCTL1 &= ~(DIVA1 + DIVA0);          /* remove /8 divisor from ACLK again */
#endif
}

void board_init()
{
    msp430_cpu_init();
    msb_ports_init();

    LED_RED_ON;

    msp430_set_cpu_speed(7372800uL);
}