ccs的DAC产生正弦波的代码

以下是一个基于C语言的DAC产生正弦波的代码示例：

#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <linux/ioctl.h>
#include <linux/soundcard.h>

#define PI 3.1415926535

int main(int argc, char* argv[])
{
    int fd;
    int sample_rate = 44100;
    int bits_per_sample = 16;
    int channels = 1;
    int frames_per_period = sample_rate; 
    int frames_per_buffer = frames_per_period;

    unsigned char buf[frames_per_buffer * bits_per_sample / 8 * channels];

    short* ptr = (short*)buf;
    for (int i = 0; i < frames_per_buffer; ++i)
    {
        double t = (double)i / sample_rate;
        double wave = sin(2 * PI * 440 * t);
        *ptr++ = (short)(wave * 32767);
    }

    fd = open("/dev/dsp", O_WRONLY);
    ioctl(fd, SNDCTL_DSP_SETFMT, &bits_per_sample);
    ioctl(fd, SNDCTL_DSP_CHANNELS, &channels);
    ioctl(fd, SNDCTL_DSP_SPEED, &sample_rate);
    while (1)
    {
        write(fd, buf, sizeof(buf));
    }

    close(fd);

    return 0;
}

此代码使用了/dev/dsp设备接口来输出声音，使用了IOCTL来设置采样率、位深、通道数等参数。在每一次循环中，通过计算正弦波的采样值，并将其写入到输出缓冲区中进行输出。