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事实上,要使TQ210板子上的蜂鸣器发声是非常容易的,因为天嵌给TQ210的蜂鸣器为有源蜂鸣器,只要给蜂鸣器供电,蜂鸣器就会发出固定频率的声音。
TQ210板子上的蜂鸣器接在TOUT1引脚,只要给它高电平,蜂鸣器就会发声。
如下代码:
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01./* 配置GPD0[1]为输出 */
02. GPD0CON &= ~(0xF << 4);
03. GPD0CON |= 1 << 4;
04. /* GPD0[1]输出高电平即可使蜂鸣器发声 */
05. GPD0DAT |= 1 << 1;
S5PV210包含5个32位的脉宽调制定时器。这些定时器都可产生中断。每个定时器可选择输入时钟为PCLK或SCLK_PWM。
定时器的操作比较简单,下面列出操作步骤:
1、设置TCFG0寄存器:配置定时器的一级分频值
1、设置TCFG1寄存器:配置定时器的二级分频值
3、设置TCNTBn寄存器:递减计数器缓冲寄存器
3、设置TCMPBn寄存器:比较缓冲寄存器
4、设置TCON寄存器:
(1)手动更新on(执行后,CPU会把TCNTBn的值加载到递减计数器中)
(2)手动更新off、自动重载、启动定时器
当递减计数器的值减到和TCMPBn的值相等时,则翻转输出引脚极性;
当递减计数器的值减到0时,如果使能了定时器中断则产生中断,如果使能了自动重载则重载TCNTBn的值到递减计数器,开始重新计数
频率计算:
我之前的时钟配置为PCLK_PSYS=66MHz,这里就由它为定时器提供时钟源。
Timer Input Clock Frequency = PCLK / ( {prescaler value + 1} ) / {divider value}
我的配置为:prescaler value = 65
divider value = 8
Timer Input Clock Frequency = 66MHz / (65 + 1) / 8 = 125000
假设输出频率为n,则
TCNTB1 = 1125000 / n
比如输出1Hz,占空比为50%
则
TCNTB1 = 125000 / 1;
TCMPB1 = TCNTB1 / 2;
具体代码如下:
start.S
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01..global _start /* 声明一个全局的标号 */
02._start:
03.
04. bl clock_init
05.
06. bl main /* 跳转到C函数去执行 */
07.
08.halt:
09. b halt
clock.c
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01.#define APLLCON0 *((volatile unsigned int *)0xE0100100)
02.#define MPLLCON *((volatile unsigned int *)0xE0100108)
03.#define EPLLCON0 *((volatile unsigned int *)0xE0100110)
04.#define VPLLCON *((volatile unsigned int *)0xE0100120)
05.#define CLK_SRC0 *((volatile unsigned int *)0xE0100200)
06.#define CLK_DIV0 *((volatile unsigned int *)0xE0100300)
07.#define CLK_DIV1 *((volatile unsigned int *)0xE0100304)
08.#define CLK_DIV2 *((volatile unsigned int *)0xE0100308)
09.#define CLK_DIV3 *((volatile unsigned int *)0xE010030C)
10.
11.void clock_init()
12.{
13. /* 1、设置PLL_LOCK寄存器(这里使用默认值) */
14. /* 2、设置PLL_CON寄存器(使用芯片手册推荐的值) */
15. APLLCON0 = (1 << 0) | (3 << 8) | (125 << 16) | (1 << 31); /* FOUTAPLL = 1000MHz */
16. MPLLCON = (1 << 0) | (12 << 8) | (667 << 16) | (1 << 31); /* FOUTMPLL = 667MHz */
17. EPLLCON0 = (1 << 0) | (12 << 8) | (667 << 16) | (1 << 31); /* FOUTEPLL = 96MHz */
18. VPLLCON = (3 << 0) | (6 << 8) | (108 << 16) | (1 << 31); /* FOUTVPLL = 54MHz */
19.
20. /* 3、选择PLL为时钟输出 */
21. /* MOUT_MSYS = SCLKAPLL = 1000MHz
22. ** MOUT_DSYS = SCLKMPLL = 667MHz
23. ** MOUT_PSYS = SCLKMPLL = 667MHz
24. */
25. CLK_SRC0 = (1 << 0) | (1 << 4) | (1 << 8) | (1 << 12);
26.
27. /* 4、设置系统时钟分频值 */
28. /* freq(ARMCLK) = MOUT_MSYS / (APLL_RATIO + 1) = 1000MHz / (0 + 1) = 1000MHz
29. ** freq(HCLK_MSYS) = ARMCLK / (HCLK_MSYS_RATIO + 1) = 1000MHz / (4 + 1) = 200MHz
30. ** freq(PCLK_MSYS) = HCLK_MSYS / (PCLK_MSYS_RATIO + 1) = 200MHz / (1 + 1) = 100MHz
31. ** freq(HCLK_DSYS) = MOUT_DSYS / (HCLK_DSYS_RATIO + 1) = 667 / (3 + 1) = 166MHz
32. ** freq(PCLK_DSYS) = HCLK_DSYS / (PCLK_DSYS_RATIO + 1) = 166 / (1 + 1) = 83MHz
33. ** freq(HCLK_PSYS) = MOUT_PSYS / (HCLK_PSYS_RATIO + 1) = 667 / (4 + 1) = 133MHz
34. ** freq(PCLK_PSYS) = HCLK_PSYS / (PCLK_PSYS_RATIO + 1) = 133 / (1 + 1) = 66MHz
35. */
36. CLK_DIV0 = (0 << 0) | (4 << 8) | (1 << 12) | (3 << 16) | (1 << 20) | (4 << 24) | (1 << 28);
37.}
main.c
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01.#define GPD0CON *((volatile unsigned int *)0xE02000A0)
02.#define GPD0DAT *((volatile unsigned int *)0xE02000A4)
03.
04.#define TCFG0 *((volatile unsigned int *)0xE2500000)
05.#define TCFG1 *((volatile unsigned int *)0xE2500004)
06.#define TCON *((volatile unsigned int *)0xE2500008)
07.#define TCNTB1 *((volatile unsigned int *)0xE2500018)
08.#define TCMPB1 *((volatile unsigned int *)0xE250001C)
09.#define TCNTO1 *((volatile unsigned int *)0xE2500020)
10.
11.int main()
12.{
13.#if 0
14. /* 配置GPD0[1]为输出 */
15. GPD0CON &= ~(0xF << 4);
16. GPD0CON |= 1 << 4;
17. /* GPD0[1]输出高电平即可使蜂鸣器发声 */
18. GPD0DAT |= 1 << 1;
19.#endif
20. /* 配置GPD0[1]为定时器1输出:TOUT1 */
21. GPD0CON &= ~(0xF << 4);
22. GPD0CON |= 2 << 4;
23.
24. /*
25. ** 配置定时器输入频率
26. ** Timer Input Clock Frequency = PCLK / ( {prescaler value + 1} ) / {divider value}
27. ** = 66MHz / (65 + 1) / 8 = 125000
28. ** 假设输出频率为n,则
29. ** TCNTB1 = 1125000 / n
30. */
31. TCFG0 = 65;
32. TCFG1 = 3 << 4;
33.
34. /* 产生1Hz,占空比为50%的输出频率 */
35. TCNTB1 = 125000 / 1;
36. TCMPB1 = TCNTB1 / 2;
37.
38. TCON = (1 << 9); /* 手动更新on */
39. TCON = (1 << 8) | (1 << 11); /* 启动定时器/手动更新off/自动重载 */
40.
41. while (1);
42.
43. return 0;
44.}
Makefile
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01.beeper.bin: start.o clock.o main.o
02. arm-linux-ld -Ttext 0xD0020010 -o key.elf $^
03. arm-linux-objcopy -O binary key.elf $@
04. arm-linux-objdump -D key.elf > key.dis
05.
06.%.o : %.c
07. arm-linux-gcc -c $< -o $@
08.%.o : %.S
09. arm-linux-gcc -c $< -o $@
10.
11.clean:
12. rm *.o *.elf *.bin *.dis
烧写过程见《TQ210裸机编程(5)——系统时钟配置》
转载请注明来源:http://blog.csdn.net/zjhsucceed_329/
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