来帮我看看采样的问题

目前mcbsp采集i2s接口数据，不接ad时对地3.3v，接ad后采集到的数据都是1，也就是0xffff，以下是我的配置函数，帮我看看哪里有误。

	EALLOW;
	McbspaRegs.DRR1.all=0X0000;
	McbspaRegs.DRR2.all=0X0000;
	////////////////////////////////////
	 McbspaRegs.SPCR1.bit.RRST=0; // Receiver reset
	 McbspaRegs.SPCR2.bit.FRST=0;
	 McbspaRegs.SPCR2.bit.GRST=0;
	 //////////////////////////////////
	 McbspaRegs.SPCR1.all=0x2000;
	 delay_loop();
	 McbspaRegs.RCR1.all=0x00A0;
	 delay_loop();
	 McbspaRegs.RCR2.all=0x80A6;
	 delay_loop();
	 McbspaRegs.SRGR1.all=0X219F;
	 delay_loop();
	 McbspaRegs.SRGR2.all=0x3041;
	 delay_loop();
	 McbspaRegs.SRGR1.bit.CLKGDV=5;
	 delay_loop();
	 McbspaRegs.PCR.bit.FSRM=1;
	 delay_loop();
	 McbspaRegs.PCR.bit.CLKRM=1;
	 delay_loop();
	 McbspaRegs.PCR.bit.CLKRP=0;
	 delay_loop();
	 McbspaRegs.PCR.bit.SCLKME=0;
	 delay_loop();
	 McbspaRegs.RCR2.bit.RCOMPAND=0;
	 delay_loop();
	 McbspaRegs.RCR2.bit.RCOMPAND=0;
	 delay_loop();
	 McbspaRegs.PCR.bit.FSRP=1;
	 delay_loop();
	 McbspaRegs.SRGR2.bit.FPER=63;
	 delay_loop();
	 McbspaRegs.SRGR1.bit.FWID=31;
	 delay_loop();
	 McbspaRegs.RCR1.bit.RFRLEN1=1;
	 delay_loop();
	 McbspaRegs.RCR2.bit.RFRLEN2=1;
	 delay_loop();
	 McbspaRegs.RCR2.bit.RPHASE=1;
	 delay_loop();
	 McbspaRegs.RCR1.bit.RWDLEN1=4;
	 delay_loop();
	 McbspaRegs.RCR2.bit.RWDLEN2=4;
	 delay_loop();
	 McbspaRegs.RCR2.bit.RFIG=0;
	 delay_loop();
	 McbspaRegs.RCR2.bit.RDATDLY=01;
	 delay_loop();
	McbspaRegs.SPCR1.bit.RJUST=01;
	delay_loop();
	McbspaRegs.SPCR1.bit.RRDY=0;
	delay_loop();
	 McbspaRegs.PCR.bit.CLKRP=0;
	 delay_loop();
	asm (" NOP ");      // Wait at least 2 SRG clock cycles
	asm (" NOP ");  
	McbspaRegs.SPCR2.bit.GRST=1; // Enable the sample rate generator
    delay_loop();         
    delay_loop();       // Wait at least 2 SRG clock cycles
    McbspaRegs.SPCR1.bit.RRST=1; // Release RX from Reset
    delay_loop();
    McbspaRegs.SPCR2.bit.FRST=1; // Frame Sync Generator reset
    delay_loop();
	EDIS;
	asm (" NOP ");
	asm (" NOP ");      // Wait at least 2 SRG clock cycles
	asm (" NOP ");