CC2530

1. 14位的
2.参考如下程序和注释.在z-stack->demosensor.c中有
static int8 readTemp(void)
[
 static uint16 voltageAtTemp22;
 static uint8 bCalibrate=TRUE; // Calibrate the first time the temp sensor is read
 uint16 value;
 int8 temp;
 #if defined (HAL_MCU_CC2530)
 ATEST = 0x01;
 TR0  |= 0x01;
 /* Clear ADC interrupt flag */
 ADCIF = 0;
 ADCCON3 = (HAL_ADC_REF_125V | HAL_ADC_DEC_512 | HAL_ADC_CHN_TEMP);
 /* Wait for the conversion to finish */
 while ( !ADCIF );
 /* Get the result */
 value = ADCL;
 value |= ((uint16) ADCH) << 8;
 // Use the 12 MSB of adcValue
 value >>= 4;
 /*
  * These parameters are typical values and need to be calibrated
  * See the datasheet for the appropriate chip for more details
  * also, the math below may not be very accurate
  */
   /* Assume ADC = 1480 at 25C and ADC = 4/C */
 #define VOLTAGE_AT_TEMP_25        1480
 #define TEMP_COEFFICIENT          4
 // Calibrate for 22C the first time the temp sensor is read.
 // This will assume that the demo is started up in temperature of 22C
 if(bCalibrate) [
   voltageAtTemp22=value;
   bCalibrate=FALSE;
 ]
 temp = 22 + ( (value - voltageAtTemp22) / TEMP_COEFFICIENT );
 // Set 0C as minimum temperature, and 100C as max
 if( temp >= 100)
 [
   return 100;
 ]
 else if (temp <= 0) [
   return 0;
 ]
 else [
   return temp;
 ]
 // Only CC2530 is supported
 #else
 return 0;
 #endif
]
                                                                          

value = ADCL; value |= ((uint16) ADCH) << 8; // Use the 12 MSB of adcValue value >>= 4;
上面这句话不就是首先把采集的数据存储为16位数么，然再右移四位 其实有效位刚刚好为12位,那么到底多少位呢？