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Diffstat (limited to 'libmaple/timers.h')
| -rw-r--r-- | libmaple/timers.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/libmaple/timers.h b/libmaple/timers.h new file mode 100644 index 0000000..18b0afb --- /dev/null +++ b/libmaple/timers.h @@ -0,0 +1,145 @@ +/* ***************************************************************************** + * 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/>. + * + * Created: 12/18/09 02:38:10 + * Copyright (c) 2009 Perry L. Hung. All rights reserved. + * + * ****************************************************************************/ + +/** + * @file timers.h + * + * @brief Timer prototypes and various definitions + */ + +/* Note to self: + * The timer clock frequencies are automatically fixed by hardware. + * There are two cases: + * 1. if the APB prescaler is 1, the timer clock frequencies are + * set to the same frequency as that of the APB domain to which + * the timers are connected. + * 2. otherwise, they are set to twice (x2) the frequency of the + * APB domain to which the timers are connected. + * See stm32 manual, 77/995 + * + * hence, 72 mhz timers + * */ + +/* Maple Timer channels: + * Timer Maple Pin STM32 Pin Type + * TIM1_CH1 D6 PA8 Advanced + * TIM1_CH2 D7 PA9 Advanced + * TIM1_CH3 D8 PA10 Advanced + * + * TIM2_CH1 D2 PA0 + * TIM2_CH2 D3 PA1 + * TIM2_CH3 D1 PA2 + * TIM2_CH4 D0 PA3 + * + * TIM3_CH1 D12 PA6 + * TIM3_CH2 D11 PA7 + * TIM3_CH3 EXT7 PB0 + * TIM3_CH4 EXT8 PB1 + * + * TIM4_CH1 EXT5 PB6 + * TIM4_CH1 EXT9 PB7 + * TIM4_CH1 EXT15 PB8 + * TIM4_CH1 EXT4 PB9 + * + * Not supported: + * TIM1_CH4 USBDM, not available PA11 Advanced + * TIM1_CH1_N EXT12 PB13 + * TIM1_CH2_N EXT13 PB14 + * TIM1_CH3_N EXT14 PB15 + * */ + +/* I don't like the Arduino API for dealing with pin modes. + * How about... + * + * pinMode(digitalPin, PWM); + * pwmWrite(digitalPin) */ + + +#ifndef _TIMERS_H_ +#define _TIMERS_H_ +#include <inttypes.h> + +#ifdef __cplusplus +extern "C"{ +#endif + +typedef volatile uint32_t* TimerCCR; + +#define TIMER1_BASE 0x40012C00 +#define TIMER2_BASE 0x40000000 +#define TIMER3_BASE 0x40000400 +#define TIMER4_BASE 0x40000800 + +#define ARPE BIT(7) // Auto-reload preload enable +#define NOT_A_TIMER 0 + +#define TIMER1_CH1_CCR (TimerCCR)(TIMER1_BASE + 0x34) +#define TIMER1_CH2_CCR (TimerCCR)(TIMER1_BASE + 0x38) +#define TIMER1_CH3_CCR (TimerCCR)(TIMER1_BASE + 0x3C) +#define TIMER1_CH4_CCR (TimerCCR)(TIMER1_BASE + 0x40) + +#define TIMER2_CH1_CCR (TimerCCR)(TIMER2_BASE + 0x34) +#define TIMER2_CH2_CCR (TimerCCR)(TIMER2_BASE + 0x38) +#define TIMER2_CH3_CCR (TimerCCR)(TIMER2_BASE + 0x3C) +#define TIMER2_CH4_CCR (TimerCCR)(TIMER2_BASE + 0x40) + +#define TIMER3_CH1_CCR (TimerCCR)(TIMER3_BASE + 0x34) +#define TIMER3_CH2_CCR (TimerCCR)(TIMER3_BASE + 0x38) +#define TIMER3_CH3_CCR (TimerCCR)(TIMER3_BASE + 0x3C) +#define TIMER3_CH4_CCR (TimerCCR)(TIMER3_BASE + 0x40) + +#define TIMER4_CH1_CCR (TimerCCR)(TIMER4_BASE + 0x34) +#define TIMER4_CH2_CCR (TimerCCR)(TIMER4_BASE + 0x38) +#define TIMER4_CH3_CCR (TimerCCR)(TIMER4_BASE + 0x3C) +#define TIMER4_CH4_CCR (TimerCCR)(TIMER4_BASE + 0x40) + + +/* Turn on timer with prescale as the divisor + * void timer_init(uint32_t timer, uint16_t prescale) + * timer -> {1-4} + * prescale -> {1-65535} + * */ +void timer_init(uint8_t, uint16_t); +void timers_disable(void); +void timers_disable_channel(uint8, uint8); + +/* Turn on PWM with duty_cycle on the specified channel in timer. + * This function takes in a pointer to the corresponding CCR + * register for the pin cause it saves pwmWrite() a couple of + * cycles. + * + * void timer_pwm(uint8_t channel, uint8_t duty_cycle); + * channel -> {TIMERx_CHn_CCR} + * duty_cycle -> {0-65535} + * + * PRECONDITIONS: + * pin has been set to alternate function output + * timer has been initialized + */ +static inline void timer_pwm_write_ccr(TimerCCR CCR, uint16_t duty_cycle) { + *CCR = duty_cycle; +} + +#ifdef __cplusplus +} // extern "C" +#endif + + +#endif + |