/*
 * noicegen.c
 *
 * Copyright 2014 Edward V. Emelianoff <eddy@sao.ru>
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */

#include "noicegen.h"

void configure_timers(){
	/**** TIMERS TIM1 - 16MHz, TIM2 - 1MHz ****/
	TIM1_PSCRH = 0; // this timer have 16 bit prescaler
	TIM1_PSCRL = 0; // LSB should be written last as it updates prescaler
	TIM2_PSCR = 4;
	// Timer1 is PWM sound level generator
	// Timer2 runs with F to change voltage level (F - frequency of sound)
	TIM1_ARRH = 0;
	TIM1_ARRL = 255;
	TIM1_CCR1H = 0; TIM1_CCR1L = 127; // default: 50%
	// channel 1 generates PWM pulses
	TIM1_CCMR1 = 0x60; // OC1M = 110b - PWM mode 1 ( 1 -> 0)
	//TIM1_CCMR1 = 0x70; // OC1M = 111b - PWM mode 2 ( 0 -> 1)
	TIM1_CCER1 =  1; // Channel 1 is on. Active is high
	//TIM1_CCER1 =  3; // Channel 1 is on. Active is low
	// default period: 33ms (30Hz)
	TIM2_ARRH = 128; TIM2_ARRL = 232; // 0x80E8 = 33000
	// interrupts: update for timer 2, none for timer 1
	TIM1_IER = 0;
	TIM2_IER = TIM_IER_UIE;
	// enable PWM output for timer1
	TIM1_BKR |= 0x80; // MOE
}