电子技术论坛_中国专业的电子工程师学习交流社区-中电网技术论坛

标题: 读取串行AD采样数据 [打印本页]

作者: reporter 时间: 2013-9-16 11:02 标题: 读取串行AD采样数据

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)
{
&nbsp; &nbsp;EALLOW;
McbspaRegs.SPCR2.all=0x0000;&nbsp;&nbsp;// Reset FS generator, sample rate generator &amp; transmitter
McbspaRegs.SPCR1.all=0x0000;&nbsp;&nbsp;// Reset Receiver, Right justify word
McbspaRegs.MFFINT.all=0x0;&nbsp; &nbsp;// Disable all interrupts
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.MFFST.all=0x0;&nbsp; &nbsp;&nbsp;&nbsp;// Clear all status bits
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.SPCR1.bit.CLKSTP=2;&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.PCR.bit.CLKXP=0;&nbsp; &nbsp; //发送数据在上升沿
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.PCR.bit.CLKRP=0;&nbsp; &nbsp; //接收数据在下降沿
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.PCR.bit.CLKXM=1;&nbsp; &nbsp;//CLKX设置为输出，SPI工作在主动模式
&nbsp; &nbsp;&nbsp;&nbsp;delay_loop();
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.PCR.bit.SCLKME=0;&nbsp; &nbsp;
&nbsp; &nbsp; McbspaRegs.SRGR2.bit.CLKSM=1;&nbsp;&nbsp;//选择采样速率发生器输入时钟源
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.SRGR1.bit.CLKGDV=0x03;&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.PCR.bit.FSXM=1;&nbsp; &nbsp;&nbsp; &nbsp; //FSX为输出引脚
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.SRGR2.bit.FSGM=0;//采样速率器帧同步信号驱动发送帧同步信号
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.PCR.bit.FSXP=1;&nbsp; &nbsp;&nbsp; &nbsp;//FSX低电平有效
&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; McbspaRegs.XCR2.bit.XDATDLY=1;&nbsp;&nbsp;//发送一位延时
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.RCR2.bit.RDATDLY=1;&nbsp;&nbsp;//接收一位延时
&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; McbspaRegs.XCR2.bit.XPHASE=0;&nbsp;&nbsp;//发送使用单相位帧
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.RCR2.bit.RPHASE=0;&nbsp;&nbsp;//接收使用单相位帧
&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; McbspaRegs.XCR1.bit.XFRLEN1=0; //发送帧长度为一个串行字
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.RCR1.bit.RWDLEN1=0; //接收帧长度为一个串行字
&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; McbspaRegs.XCR1.bit.XWDLEN1=2; //发送字长度为16位
&nbsp; &nbsp;&nbsp;&nbsp;McbspaRegs.RCR1.bit.RWDLEN1=2; //接收字长度为16位&nbsp; &nbsp;&nbsp; &nbsp;
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; McbspaRegs.SPCR2.bit.GRST=1;&nbsp; &nbsp;//复位采样速率生成器
&nbsp; &nbsp;&nbsp;&nbsp;clkg_delay_loop();&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;// Wait at least 2 CLKG cycles
McbspaRegs.SPCR2.bit.XRST=1;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;// Release TX from Reset
McbspaRegs.SPCR1.bit.RRST=1;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;// Release RX from Reset
clkg_delay_loop();&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;// Wait at least 2 CLKG cycles
McbspaRegs.SPCR2.bit.FRST=1;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;// Frame Sync Generator reset

}

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

欢迎光临电子技术论坛_中国专业的电子工程师学习交流社区-中电网技术论坛 (http://bbs.eccn.com/)