问 uint32 ADC_Data;
   PINSEL0 = (PINSEL0 & 0xFFCFFFFF)|0x00300000;      // AD1.2
   
   AD1CR =   (1 << 2)                       |
            ((Fpclk / 1000000 - 1) << 8)    |                (0 << 16)            |                
        (0 << 17)            |                
        （1 << 21)        |                      
        (0 << 22)            |                    (1 << 24)                       |
        （0 << 27);                            
    DelayNS (5);

ADC_Data = AD1DR2;

AD1CR = (AD1CR & 0xffffff00)|(1 << 2)|(1 << 24);
      while ((AD1DR2 & 0x80000000) == 0);    
      AD1CR |= 1 << 24;                         while ((AD1DR2 & 0x80000000) == 0);    
      ADC_Data = AD1DR2;                          ADC_Data = (ADC_Data >> 6) & 0x3ff;
      ADC_Data = ADC_Data * 2480;                   ADC_Data = ADC_Data / 1024;
上面是我ad的程序，为什么会停在while处，不能完成ad转换！
ad1.2的管脚已经与测试量连接，并没有悬空。 答 1: 看看下面的链接http://groups.yahoo.com/group/lpc2000/files/