读取串行AD采样数据

1万 · 2013-9-15 17:04

高手帮忙看看，mcbsp配置成SPI主动模式读取串行AD采样数据。谢谢

void InitMcbsp(void)
{
EALLOW;
McbspaRegs.SPCR2.all=0x0000;  // Reset FS generator, sample rate generator & transmitter
McbspaRegs.SPCR1.all=0x0000;  // Reset Receiver, Right justify word
McbspaRegs.MFFINT.all=0x0; // Disable all interrupts
   McbspaRegs.MFFST.all=0x0;    // Clear all status bits
   McbspaRegs.SPCR1.bit.CLKSTP=2;
   McbspaRegs.PCR.bit.CLKXP=0; //发送数据在上升沿
   McbspaRegs.PCR.bit.CLKRP=0; //接收数据在下降沿
   McbspaRegs.PCR.bit.CLKXM=1; //CLKX设置为输出，SPI工作在主动模式
   delay_loop();
   McbspaRegs.PCR.bit.SCLKME=0;
McbspaRegs.SRGR2.bit.CLKSM=1;  //选择采样速率发生器输入时钟源
   McbspaRegs.SRGR1.bit.CLKGDV=0x03;
   McbspaRegs.PCR.bit.FSXM=1;    //FSX为输出引脚
   McbspaRegs.SRGR2.bit.FSGM=0;//采样速率器帧同步信号驱动发送帧同步信号
   McbspaRegs.PCR.bit.FSXP=1;    //FSX低电平有效

McbspaRegs.XCR2.bit.XDATDLY=1;  //发送一位延时
   McbspaRegs.RCR2.bit.RDATDLY=1;  //接收一位延时

McbspaRegs.XCR2.bit.XPHASE=0;  //发送使用单相位帧
   McbspaRegs.RCR2.bit.RPHASE=0;  //接收使用单相位帧

McbspaRegs.XCR1.bit.XFRLEN1=0; //发送帧长度为一个串行字
   McbspaRegs.RCR1.bit.RWDLEN1=0; //接收帧长度为一个串行字

McbspaRegs.XCR1.bit.XWDLEN1=2; //发送字长度为16位
   McbspaRegs.RCR1.bit.RWDLEN1=2; //接收字长度为16位

McbspaRegs.SPCR2.bit.GRST=1; //复位采样速率生成器
   clkg_delay_loop();                // Wait at least 2 CLKG cycles
McbspaRegs.SPCR2.bit.XRST=1;       // Release TX from Reset
McbspaRegs.SPCR1.bit.RRST=1;       // Release RX from Reset
clkg_delay_loop();                // Wait at least 2 CLKG cycles
McbspaRegs.SPCR2.bit.FRST=1;       // Frame Sync Generator reset

}

void InitAdc(void)
{
InitMcbsp();

while(McbspaRegs.SPCR2.bit.XRDY!=1);
McbspaRegs.DXR1.all=0xA000;
while(McbspaRegs.SPCR1.bit.RRDY!=1);
Adcresult[0]=McbspaRegs.DRR1.all;

while(McbspaRegs.SPCR2.bit.XRDY!=1);
McbspaRegs.DXR1.all=0xC000;;
while(McbspaRegs.SPCR1.bit.RRDY!=1);
Adcresult[0]=McbspaRegs.DRR1.all;

while(McbspaRegs.SPCR2.bit.XRDY!=1);
McbspaRegs.DXR1.all=0x9C18;;
while(McbspaRegs.SPCR1.bit.RRDY!=1);
Adcresult[0]=McbspaRegs.DRR1.all;

}

void delay_loop(void)    // Delay function used while initializing the registers
{
   long    i;
   for (i = 0; i<4; i++);
}
void clkg_delay_loop(void)
{
   long    i;
   for (i = 0; i<16; i++); //delay in McBsp init. must be at least 2 SRG cycles
}