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authorPerry Hung <iperry@alum.mit.edu>2010-03-30 22:03:00 -0400
committerPerry Hung <iperry@alum.mit.edu>2010-03-30 22:03:00 -0400
commit2c33d55bae8f9e0e009634072ab05302fc734a65 (patch)
tree63285f96e795fc423cd5bf573340d12f6c8d5513 /libmaple/timers.h
parent23149e9706ff0a6a338e13804456dff4c655e34b (diff)
parent1d3861ef93f8423176c6010ab606abdab00a7cbd (diff)
downloadlibrambutan-2c33d55bae8f9e0e009634072ab05302fc734a65.tar.gz
librambutan-2c33d55bae8f9e0e009634072ab05302fc734a65.zip
Merge branch 'master' into rcc-dev
Conflicts: Makefile
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+/* *****************************************************************************
+ * 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
+