nes-proj/cpu/mc1322x/lib/include/pwm.h

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2011-03-11 20:55:32 +00:00
/*
* Copyright (c) 2010, Mariano Alvira <mar@devl.org> and other contributors
* to the MC1322x project (http://mc1322x.devl.org)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of libmc1322x: see http://mc1322x.devl.org
* for details.
*
*
*/
#ifndef PWM_H
#define PWM_H
/* Initialize PWM output.
timer_num = 0, 1, 2, 3
rate = desired rate in Hz,
duty = desired duty cycle. 0=always off, 65536=always on.
enable_timer = whether to actually run the timer, versus just configuring it
Returns actual PWM rate. */
uint32_t pwm_init_ex(int timer_num, uint32_t rate, uint32_t duty, int enable_timer);
/* Initialize PWM output, helper macros
timer = TMR0, TMR1, TMR2, TMR2
rate = desired rate in Hz,
duty = desired duty cycle. 0=always off, 65536=always on.
Returns actual PWM rate. */
#define pwm_init(timer,rate,duty) pwm_init_ex(TMR_NUM(timer), rate, duty, 1)
#define pwm_init_stopped(timer,rate,duty) pwm_init_ex(TMR_NUM(timer), rate, duty, 0)
/* Change duty cycle. Safe to call at any time.
timer_num = 0, 1, 2, 3
duty = desired duty cycle. 0=always off, 65536=always on.
*/
void pwm_duty_ex(int timer_num, uint32_t duty);
/* Change duty cycle. Safe to call at any time.
timer = TMR0, TMR1, TMR2, TMR2
duty = desired duty cycle. 0=always off, 65536=always on.
*/
#define pwm_duty(timer,duty) pwm_duty_ex(TMR_NUM(timer), duty)
#endif