总共有16路的DAC输出，通过SPI通信，输出直流电压都很准，但是当我输出正弦波的时候就出问题了，看图


这是给16位的正弦数组
static const u16 auchSin[]={
0x8000,0x8647,0x8C8B,0x92C7,0x98F8,0x9F19,0xA527,0xAB1F,
0xB0FB,0xB6B9,0xBC56,0xC1CD,0xC71C,0xCC3F,0xD133,0xD5F5,
0xDA82,0xDED7,0xE2F1,0xE6CF,0xEA6D,0xEDC9,0xF0E2,0xF3B5,
0xF641,0xF884,0xFA7C,0xFC29,0xFD89,0xFE9C,0xFF61,0xFFD8,
0xFFFF,0xFFD8,0xFF61,0xFE9C,0xFD89,0xFC29,0xFA7C,0xF884,
0xF641,0xF3B5,0xF0E2,0xEDC9,0xEA6D,0xE6CF,0xE2F1,0xDED7,
0xDA82,0xD5F5,0xD133,0xCC3F,0xC71C,0xC1CD,0xBC56,0xB6B9,
0xB0FB,0xAB1F,0xA527,0x9F19,0x98F8,0x92C7,0x8C8B,0x8647,
0x7FFF,0x79B8,0x7374,0x6D38,0x6707,0x60E6,0x5AD8,0x54E0,
0x4F04,0x4946,0x43A9,0x3E32,0x38E3,0x33C0,0x2ECC,0x2A0A,
0x257D,0x2128,0x1D0E,0x1930,0x1592,0x1236,0x0F1D,0x0C4A,
0x09BE,0x077B,0x0583,0x03D6,0x0276,0x0163,0x009E,0x0027,
0x0000,0x0027,0x009E,0x0163,0x0276,0x03D6,0x0583,0x077B,
0x09BE,0x0C4A,0x0F1D,0x1236,0x1592,0x1930,0x1D0E,0x2128,
0x257D,0x2A0A,0x2ECC,0x33C0,0x38E3,0x3E32,0x43A9,0x4946,
0x4F04,0x54E0,0x5AD8,0x60E6,0x6707,0x6D38,0x7374,0x79B8
};

DAC是16位的，输出是【-10,10】V，求大神帮忙解答