dsp280x_adc.c

TI DSP TMS320F28xx ADC 典型代码。

// TI File $Revision: /main/1 $
// Checkin $Date: December 1, 2004   11:11:30 $
//###########################################################################
//
// FILE:	DSP28xx_Adc.c
//
// TITLE:	DSP280x ADC Initialization & Support Functions.
//
//###########################################################################
// $TI Release: DSP280x, DSP2801x Header Files V1.41 $
// $Release Date: August 7th, 2006 $
//###########################################################################

#include "DSP280x_Device.h"     // DSP280x Headerfile Include File
#include "DSP280x_Examples.h"   // DSP280x Examples Include File

#define ADC_usDELAY  5000L
#define	ADC_usDELAY1 8000L
#define ADC_usDELAY2 20L

//---------------------------------------------------------------------------
// InitAdc: 
//---------------------------------------------------------------------------
// This function initializes ADC to a known state.
//
// PLEASE NOTE, ADC INIT IS DIFFERENT ON 281x vs 280x DEVICES!!!
//
void Init280xAdc(void)
{
    extern void DSP28x_usDelay(Uint32 Count);

    // To powerup the ADC the ADCENCLK bit should be set first to enable
    // clocks, followed by powering up the bandgap, reference circuitry, and ADC core.
    // Before the first conversion is performed a 5ms delay must be observed 
    // after power up to give all analog circuits time to power up and settle

    // Please note that for the delay function below to operate correctly the 
	// CPU_CLOCK_SPEED define statement in the DSP280x_Examples.h file must 
	// contain the correct CPU clock period in nanoseconds. 

    AdcRegs.ADCTRL3.all = 0x00E0;  // Power up bandgap/reference/ADC circuits
    DELAY_US(ADC_usDELAY);         // Delay before converting ADC channels
}	

void Init281xAdc(void)
{
	extern void DSP28x_usDelay(Uint32 Count);
	
    // To powerup the ADC the ADCENCLK bit should be set first to enable
    // clocks, followed by powering up the bandgap and reference circuitry.
    // After a 5ms delay the rest of the ADC can be powered up. After ADC
    // powerup, another 20us delay is required before performing the first
    // ADC conversion. Please note that for the delay function below to
    // operate correctly the CPU_CLOCK_SPEED define statement in the
    // DSP28_Examples.h file must contain the correct CPU clock period in
    // nanoseconds. For example:

	AdcRegs.ADCTRL3.bit.ADCBGRFDN = 0x3;	// Power up bandgap/reference circuitry
	DELAY_US(ADC_usDELAY1);                  // Delay before powering up rest of ADC
	AdcRegs.ADCTRL3.bit.ADCPWDN = 1;		// Power up rest of ADC
	DELAY_US(ADC_usDELAY2);                 // Delay after powering up ADC
}	


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// End of file.
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