TIMER — TIMER1 输出比较翻转
固件库: GD32F30x_Firmware_Library V3.0.3
芯片: GD32
源文件: GD32F30x_Firmware_Library_V3.0.3/Examples/TIMER/TIMER1_octoggle/main.c
功能简介
本示例演示输出比较模式。定时器计数到设定值时自动翻转/置高/置低引脚,可以生成精确的方波信号。
完整代码
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
#include "gd32f30x.h"
#include <stdio.h>
#include "gd32f307c_eval.h"
void gpio_config(void);
void timer_config(void);
/*!
\brief configure the GPIO ports
\param[in] none
\param[out] none
\retval none
*/
void gpio_config(void)
{
rcu_periph_clock_enable(RCU_GPIOA);
rcu_periph_clock_enable(RCU_AF);
/*configure PA1(TIMER1 CH1) as alternate function*/
gpio_init(GPIOA,GPIO_MODE_AF_PP,GPIO_OSPEED_50MHZ,GPIO_PIN_1);
}
void timer_config(void)
{
/* ---------------------------------------------------------------------------
TIMER1 configuration: output compare toggle mode:
TIMER1CLK = systemcoreclock / 6000=20K,
CH1 update rate = TIMER1 counter clock / CH1VAL = 20000/4000 = 5 Hz
----------------------------------------------------------------------------*/
timer_oc_parameter_struct timer_ocintpara;
timer_parameter_struct timer_initpara;
rcu_periph_clock_enable(RCU_TIMER1);
timer_deinit(TIMER1);
/* TIMER1 configuration */
timer_initpara.prescaler = 5999;
timer_initpara.alignedmode = TIMER_COUNTER_EDGE;
timer_initpara.counterdirection = TIMER_COUNTER_UP;
timer_initpara.period = 3999;
timer_initpara.clockdivision = TIMER_CKDIV_DIV1;
timer_initpara.repetitioncounter = 0;
timer_init(TIMER1,&timer_initpara);
/* CH1 configuration in OC TOGGLE mode */
timer_ocintpara.outputstate = TIMER_CCX_ENABLE;
timer_ocintpara.outputnstate = TIMER_CCXN_DISABLE;
timer_ocintpara.ocpolarity = TIMER_OC_POLARITY_HIGH;
timer_ocintpara.ocnpolarity = TIMER_OCN_POLARITY_HIGH;
timer_ocintpara.ocidlestate = TIMER_OC_IDLE_STATE_LOW;
timer_ocintpara.ocnidlestate = TIMER_OCN_IDLE_STATE_LOW;
timer_channel_output_config(TIMER1,TIMER_CH_1,&timer_ocintpara);
timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_1,3999);
timer_channel_output_mode_config(TIMER1,TIMER_CH_1,TIMER_OC_MODE_TOGGLE);
timer_channel_output_shadow_config(TIMER1,TIMER_CH_1,TIMER_OC_SHADOW_DISABLE);
/* auto-reload preload enable */
timer_auto_reload_shadow_enable(TIMER1);
timer_enable(TIMER1);
}
int main(void)
{
gpio_config();
timer_config();
while (1);
}
|
代码讲解
GPIO 配置:设置引脚为输出/输入模式,选择推挽/开漏输出,配置上拉/下拉。
定时器配置:设置预分频器(PSC)和重装载值(ARR),定时时间 = (PSC+1) × (ARR+1) / 时钟频率。