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问 这个I/O的电气特性跟其他管脚一样吗？一般为1.8~3.6V ，因为是比较器的管脚是否可以加大一点0~12V 答 1: 引用: 答 2: CACTL1 = CAON+CAREF_2;
CACTL2 = P2CA1+CAF;

if (CAOUT & CACTL2)
P1OUT &= ~ BIT3; //if CAOUT set, set P1.0
else
P1OUT |= &BIT3;



这CAOUT 怎么老为1呢？调来调去都一样，不灵拉，杨工， 答 3: P1OUT|=&BIT3这句合适吗？ 答 4: 你再对照一下这个例子，和内部功能图示比较一下。
//******************************************************************************
// MSP-FET430F1121 Demo - Comp_A Detect theashold, Set P1.0 if P2.3 > 0.25*Vcc
//
// Description; Use comparator_A to detect a voltage threshold.
// Using an external potentiometer, an unknown voltage is applied to P2.3.
// Comparator_A compares the unknown voltage to an internal reference
// voltage, in this example 0.25*VCC. If the unknown voltage is higher
// than 0.25*VCC, P1.0 is set, if not, P1.0 is reset.
//
// MSP430F1121
// _________________
// /|\ | XIN|-
// | | |
// ---|RST XOUT|-
// | | |
// R<-|P2.3 P1.0|-->LED
// | | |
// ---|VSS
//
// M.Buccini
// Texas Instruments, Inc
// January 2002
// Built with IAR Embedded Workbench Version: 1.25A
//******************************************************************************

#include "MSP430x11x1.h"

void main (void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1DIR |= BIT0; // P1.0 output
CACTL1 = CARSEL + CAREF0 + CAON; // 0.25 Vcc = -comp, on
CACTL2 = P2CA0; // P2.3 = +comp

while (1) // Test comparator_A output
{
if ((CAOUT & CACTL2) == CAOUT) P1OUT |= BIT0; // if CAOUT set, set P1.0
else P1OUT &= ~BIT0; // else reset
}
}