MSP430F427A在实验中发现应用TI官网的例程（如下），采集同一组电池电压用此例程采集到一个电压AD值A，把例程中低功耗屏蔽则又财经到一个电压AD值B。B的值比A大100个AD左右。当设置为以下设置时（SD16INCTL2 |= SD16INTDLY_0+SD16GAIN_32）B比A大400左右。请问此问题原因？
#include <msp430.h>
unsigned int result;
int main(void) {
volatile unsigned int i; // Use volatile to prevent removal
// by compiler optimization
WDTCTL = WDTPW + WDTHOLD; // Stop WDT FLL_CTL0 |= XCAP14PF;
// Configure load caps
for (i = 0; i < 10000; i++); // Delay for 32 kHz crystal to
// stabilize
SD16CTL = SD16REFON+SD16SSEL0; // 1.2V ref, SMCLK
SD16CCTL2 |= SD16SNGL+SD16IE ; // Single conv, enable interrupt
SD16INCTL2 |= SD16INTDLY0;
// Interrupt on 3rd sample
for (i = 0; i < 0x3600; i++); // Delay for 1.2V ref startup
_EINT(); // Enable general interrupts
while (1)
{
SD16CCTL2 |= SD16SC; // SET BREAKPOINT HERE
// Set bit to start conversion
_BIS_SR(LPM0_bits); // Enter LPM0
}
}
#pragma vector=SD16_VECTOR __interrupt void SD16ISR(void)
{
switch (SD16IV)
{ case 2: // SD16MEM Overflow
break;
case 4: // SD16MEM0 IFG
break;
case 6: // SD16MEM1 IFG
break;
case 8: // SD16MEM2 IFG
result = SD16MEM2; // Save CH2 results (clears IFG)
break;
}
_BIC_SR_IRQ(LPM0_bits); // Exit LPM0
}
