求大佬指点为什么我程序这样写最终得到的正弦波频率只有几百赫兹
单片机源程序如下:
#include <stc8.h> //基准电压是2.515V
#define uint8 unsigned char
#define uint16 unsigned int
sbit CS = P2^4; //片选
sbit SCLK = P2^2; //时钟
sbit DIN = P2^0; //数据入口
uint16 code tosin[256]={
0x1FF,0x20C,0x218,0x225,0x231,0x23E,0x24A,0x256,0x263,0x26F,0x27B,0x287,0x293,0x29F,0x2AB,0x2B7
,0x2C3,0x2CE,0x2DA,0x2E5,0x2F0,0x2FB,0x306,0x311,0x31B,0x326,0x330,0x33A,0x343,0x34D,0x357,0x360
,0x369,0x371,0x37A,0x382,0x38A,0x392,0x39A,0x3A1,0x3A8,0x3AF,0x3B6,0x3BC,0x3C2,0x3C8,0x3CD,0x3D3
,0x3D8,0x3DC,0x3E1,0x3E5,0x3E8,0x3EC,0x3EF,0x3F2,0x3F5,0x3F7,0x3F9,0x3FB,0x3FC,0x3FD,0x3FE,0x3FE
,0x3FE,0x3FE,0x3FE,0x3FD,0x3FC,0x3FB,0x3F9,0x3F7,0x3F5,0x3F2,0x3EF,0x3EC,0x3E8,0x3E5,0x3E1,0x3DC
,0x3D8,0x3D3,0x3CD,0x3C8,0x3C2,0x3BC,0x3B6,0x3AF,0x3A8,0x3A1,0x39A,0x392,0x38A,0x382,0x37A,0x371
,0x369,0x360,0x357,0x34D,0x343,0x33A,0x330,0x326,0x31B,0x311,0x306,0x2FB,0x2F0,0x2E5,0x2DA,0x2CE
,0x2C3,0x2B7,0x2AB,0x29F,0x293,0x287,0x27B,0x26F,0x263,0x256,0x24A,0x23E,0x231,0x225,0x218,0x20C
,0x1FF,0x1F2,0x1E6,0x1D9,0x1CD,0x1C0,0x1B4,0x1A8,0x19B,0x18F,0x183,0x177,0x16B,0x15F,0x153,0x147
,0x13B,0x130,0x124,0x119,0x10E,0x103,0x0F8,0x0ED,0x0E3,0x0D8,0x0CE,0x0C4,0x0BB,0x0B1,0x0A7,0x09E
,0x095,0x08D,0x084,0x07C,0x074,0x06C,0x064,0x05D,0x056,0x04F,0x048,0x042,0x03C,0x036,0x031,0x02B
,0x026,0x022,0x01D,0x019,0x016,0x012,0x00F,0x00C,0x009,0x007,0x005,0x003,0x002,0x001,0x000,0x000
,0x000,0x000,0x000,0x001,0x002,0x003,0x005,0x007,0x009,0x00C,0x00F,0x012,0x016,0x019,0x01D,0x022
,0x026,0x02B,0x031,0x036,0x03C,0x042,0x048,0x04F,0x056,0x05D,0x064,0x06C,0x074,0x07C,0x084,0x08D
,0x095,0x09E,0x0A8,0x0B1,0x0BB,0x0C4,0x0CE,0x0D8,0x0E3,0x0ED,0x0F8,0x103,0x10E,0x119,0x124,0x130
,0x13B,0x147,0x153,0x15F,0x16B,0x177,0x183,0x18F,0x19B,0x1A8,0x1B4,0x1C0,0x1CD,0x1D9,0x1E6,0x1F2 };
void DA_Conver(uint16 DA_Value) //进行DA转换，输入十位DA值，十六位数据，高四位无效，认为0000 //低二位为00
{
uint8 i;
DA_Value <<= 6;
CS =0; //片选DA芯片,低电平有效
SCLK = 0; //片选低电平， 时钟为上升沿时开始传送数据
for(i=0;i<12;i++) //从高位到地位依次发送
{
DIN = (bit)(DA_Value & 0x8000);
SCLK = 1;
DA_Value <<= 1; // 一位一位的进行传输
SCLK = 0;
}
CS = 1; // 关闭芯片，CS的上升沿和下降沿只有在clk为低的时候才有效
SCLK = 0;
}
void main()
{
uint16 j;
P2M0=0x00;
P2M1=0x00;
while(1)
{
for(j=0;j<255;j++)
{
DA_Conver(tosin[j]); //输出正弦波
}
}
}
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