请教PORTA口问题

只看该作者 · 2007-4-27 21:35

我使用PIC16F883对IO口进行操作,我在PORTA送0x0f,怎么RA0,RA1,RA2,RA3的电压都只有1.6V呢? 请各位帮我诊断一下。初始化芯片程序如下:
void InitChip()
{
    STATUS = 0;
    CLRWDT();
    // init interrupt module
    INTCON = 0; // disable all interrupt
    PIE1 = 0; // disable interrupt
    PIE2 = 0;
    PIR1 = 0;
    PIR2 = 0;
    RBIE = 0;
//    INTE = 0;
    INTE=0;
  //  INT1IE=0;
//   INTCON2=0;
//    INTCON3=0;
    // init power control register
     PCON = 0x03;
    RBPU = 0;
    IOCB = 0;

  //enable port B pullups, prescaler to watchdog
    // init timer0 module,prescalar set to 1:32
    // has done in OPTION_REG
    TMR0 = 0;
    T0CS =0;
    PSA = 0;
    PS2 = 1;
    PS1 = 0;
    PS0 = 0;
    // init TIMER1 module,
    // prescalar set to 1:8, turn off timer1
    T1CON = 0x30;
    TMR1H = 0;
    TMR1L = 0;
    // init TIMER2 module,
    // postscaler set to 1:5,prescalar set to 1:1, turn off timer1
    T2CON = 0X20;
    TMR2 = 0;
    PR2 = 150;


    // init CCP module
    // disable ccp1 and ccp2
    CCP1CON = 0x30;
    CCP2CON = 0;
//    CCP3CON = 0;
    // init ssp module
    // disable ssp
    SSPCON = 0;
    SSPCON2 = 0;
    SSPBUF = 0;

    // init usart module
    SPBRG = 129; // 9600 baud rate
    TXSTA = 0x04; // 8 bit transmition, disable transmition
    RCSTA = 0x00; //disable usart receiver, 8 bit receive
    //init comparator register
    CM1CON0 = 0x03;
    CM2CON0 = 0x03;
    CM2CON1 = 0x00;
    VRCON = 0;
    SRCON = 0;
    //init comparator register
    PWM1CON = 0;
    //init ad module
    ADCON1 = 0x0f; // select RA0,RA1,RA3 as digital IO
    ADCON0 = 0;
    ANSEL = 0;
    ANSELH = 0;
//    ADCON2 = 0;
}
ＩＯ操作如下
        TRISA = 0x10;
　　　　PORTA = 0x0f;
麻烦各位了！谢谢！