61 lines
1.5 KiB
C
61 lines
1.5 KiB
C
/*
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hardware.h - TAE hardware
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Copyright (C) 2009 <telekatz@gmx.de>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "hardware.h"
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#include <msp430.h>
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void init_clock(void) {
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unsigned char step;
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int last, delta;
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DCOCTL = 0x70;
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BCSCTL1 = XT2OFF | DIVA_3 | (DCO_RSEL & 0xF);
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BCSCTL2 = 0x00;
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last = 0;
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TACTL = TASSEL_2 /* Timer A clock source select: 2 - SMCLK */
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| MC_2 /* Timer A mode control: 2 - Continous up */
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| TACLR;
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TACCTL2 = CM1 /* Capture mode 1 */
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| CCIS_1 | SCS | CAP;
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for (step = 0x40; step > 0; step >>= 1) {
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while (!(TACCTL2 & CCIFG));
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delta = TACCR2 - last;
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if (delta < DCO_ACLK_DELTA) {
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DCOCTL += step;
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}
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else {
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DCOCTL -= step;
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}
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last = TACCR2;
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TACCTL2 &= ~CCIFG;
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}
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BCSCTL1 &= ~DIVA_3;
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BCSCTL2 = DIVS_1;
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TACTL = TASSEL1 /* Timer A clock source select 0 */
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| MC_2 /* Timer A mode control: 2 - Continous up */
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| TACLR;
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}
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