util.c

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//*****************************************************************************
// Author               : Christian Illy
// Created              : 19.04.2009
// Revised              : 04.06.2009
// Version              : 0.1
// Target MCU   : Fujitsu MB96300 series
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
//*****************************************************************************

#include "util.h"
#include "adc.h"
#include "mb96348hs.h"

void delay(uint16_t del) {
        uint16_t cnt;
        for (cnt = 0; cnt < del; cnt++)
                __wait_nop();
}

void delay_us(uint16_t us) {
        TMRLR3 = 7*us - 1;
        TMCSR3 = 0x1403;
        while (TMCSR3_UF == 0)
                __wait_nop();
}

void delay_ms(uint16_t ms) {
        for (; ms > 0; ms--)
                delay_us(1000);
}

void delay_s(uint16_t s) {
        for (; s > 0; s--)
                delay_ms(1000);
}

int sgn(int x) {
        return (x > 0) ? 1 : (x < 0) ? -1 : 0;
}

void intToStr(uint32_t val, uint8_t digits, uint8_t fuellChar, char* dest) {
        uint8_t i;

        if ((digits < 1) || (digits > 10)) {
                dest = 0;
                return;
        }

        for (i = 0; i < digits; i++) {
                dest[digits - i - 1] = '0' + (val % 10);
                val /= 10;
        }

        for (i = 0; i < (digits - 1); i++) {
                if (dest[i] == '0')
                        dest[i] = fuellChar;
                else
                        break;
        }

        dest[digits] = 0;
}

void intToHex(uint32_t val, uint8_t digits, uint8_t fuellChar, char* dest) {
        uint8_t i;

        if ((digits < 1) || (digits > 8)) {
                dest = 0;
                return;
        }

        for (i = 0; i < digits; i++) {
                dest[digits - i - 1] = '0' + (val % 16);
                if (dest[digits - i - 1] > '9')
                        dest[digits - i - 1] += 'A' - ':';
                val /= 16;
        }

        for (i = 0; i < (digits - 1); i++) {
                if (dest[i] == '0')
                        dest[i] = fuellChar;
                else
                        break;
        }

        dest[digits] = 0;
}


static uint32_t random_w = 0;
static uint32_t random_z = 0;

void random_init(void) {
        uint8_t i;

        adc_init();

        for (i = 0; i < 32; i++) {
                random_w |= (adc_getValue(RANDOM_INIT_PIN_START+(i%RANDOM_INIT_PIN_COUNT)) & 0x01) << i;
                delay_ms(3);
                random_z |= (adc_getValue(RANDOM_INIT_PIN_START+(i%RANDOM_INIT_PIN_COUNT)) & 0x01) << i;
                delay_ms(3);
        }
}

uint32_t random(void)
{
        /*
         * (Pseudo) random number generation from:
         * http://en.wikipedia.org/wiki/Random_number_generation#Computational_methods
         */
    random_z = 36969 * (random_z & 65535) + (random_z >> 16);
    random_w = 18000 * (random_w & 65535) + (random_w >> 16);
    return (random_z << 16) + random_w;  /* 32-bit result */
}