Specifications

© 2006 Microchip Technology Inc. DS70183A-page 16-57
Section 16. Analog-to-Digital Converter (ADC)
A
D
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16
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 */
}