Microchip Technology dsPIC33F Family Spezifikationen PDF herunterladen (Seite 57)

Section 16. Analog-to-Digital Converter (ADC)

Example 16-4: Code for Channel Scanning Using DMA (Continued)

void initDma0(void)

{

DMA0CONbits.AMODE = 2; // Configure DMA for Peripheral indirect mode

DMA0CONbits.MODE = 2; // Configure DMA for Continuous Ping-Pong mode

DMA0PAD = 0x0300; // Point DMA to ADC1BUF0

DMA0CNT = 31; // 32 DMA request (4 buffers, each with 8 words)

DMA0REQ = 13; // Select ADC1 as DMA Request source

DMA0STA = __builtin_dmaoffset(&BufferA);

DMA0STB = __builtin_dmaoffset(&BufferB);

IFS0bits.DMA0IF = 0; //Clear the DMA interrupt flag bit

IEC0bits.DMA0IE = 1; //Set the DMA interrupt enable bit

DMA0CONbits.CHEN=1; // Enable DMA

}

/*========================================================================================

_DMA0Interrupt(): ISR name is chosen from the device linker script.

========================================================================================*/

unsigned int DmaBuffer = 0;

void __attribute__((__interrupt__)) _DMA0Interrupt(void)

{

if(DmaBuffer == 0)

{

ProcessADCSamples(BufferA.Adc1Ch0);

ProcessADCSamples(BufferA.Adc1Ch1);

ProcessADCSamples(BufferA.Adc1Ch2);

ProcessADCSamples(BufferA.Adc1Ch3);

}

else

{

ProcessADCSamples(BufferB.Adc1Ch0);

ProcessADCSamples(BufferB.Adc1Ch1);

ProcessADCSamples(BufferB.Adc1Ch2);

ProcessADCSamples(BufferB.Adc1Ch3);

}

DmaBuffer ^= 1;

IFS0bits.DMA0IF = 0; //Clear the DMA0 Interrupt Flag

}

void ProcessADCSamples(unsigned int * AdcBuffer)

{

/* Do something with ADC Samples */

}

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Microchip Technology dsPIC33F Family Spezifikationen Seite 57