adc.c

cc2430的源程序

/******************************************************************************
    Filename: adc.c

    These functions/macros simplifies usage of the ADC.

    Copyright 2007 Texas Instruments, Inc.
******************************************************************************/

#include "adc.h"


/******************************************************************************
* @fn  adcSampleSingle
*
* @brief
*      This function makes the adc sample the given channel at the given
*      resolution with the given reference.
*
* @param uint8 reference
*          The reference to compare the channel to be sampled.
*        uint8 resolution
*          The resolution to use during the sample (8, 10, 12 or 14 bit)
*        uint8 input
*          The channel to be sampled.
*
* @return int16
*          The conversion result
*
******************************************************************************/
int16 adcSampleSingle(uint8 reference, uint8 resolution, uint8 channel)
{
    int16 value;

    ADC_ENABLE_CHANNEL(channel);

    ADCIF = 0;

    ADC_SINGLE_CONVERSION(reference | resolution | channel);
    while(!ADCIF);

    value  = (ADCH << 8) & 0xff00;
    value |= ADCL;

    ADC_DISABLE_CHANNEL(channel);

    //  The variable 'value' contains 16 bits where
    //     bit 15 is a sign bit
    //     bit [14 .. 0] contain the absolute sample value
    //     Only the r upper bits are significant, where r is the resolution
    //     Resolution:
    //        12   -> [14 .. 3] (bitmask 0x7FF8)
    //        10   -> [14 .. 5] (bitmask 0x7FE0)
    //         9   -> [14 .. 6] (bitmask 0x7FC0)
    //         7   -> [14 .. 8] (bitmask 0x7F00)

    return value;
}

/***********************************************************************************
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  Software unless you agree to abide by the terms of the License. The License
  limits your use, and you acknowledge, that the Software may not be modified,
  copied or distributed unless embedded on a Texas Instruments microcontroller
  or used solely and exclusively in conjunction with a Texas Instruments radio
  frequency transceiver, which is integrated into your product.  Other than for
  the foregoing purpose, you may not use, reproduce, copy, prepare derivative
  works of, modify, distribute, perform, display or sell this Software and/or
  its documentation for any purpose.

  YOU FURTHER ACKNOWLEDGE AND AGREE THAT THE SOFTWARE AND DOCUMENTATION ARE
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