MityDSP::tcDspAdc1278 Class Reference

Instances of this class create an interface to an ADS1278 24-bit analog to digital converter. More...

#include <core/DspAdc1278.h>

List of all members.

Classes
struct	tsTccMap

Public Member Functions
	tcDspAdc1278 (int mnMcBSPDevNum, unsigned int anSCLKFreq_Hz, unsigned int anFSample_Hz, int anNumChannels)
	This constructor is used to open a tcDspAdc1278 interface with the the specified settings (optional).
	~tcDspAdc1278 ()
	Default destructor.
unsigned int	GetSamples (int *apBuffer, int anNumWords, SEM_Handle ahHandle)
	Get a sample from the ADC.
int	ContinuousCapture (int *apBuffer[2], int anWordsPerBuffer, SEM_Handle ahSemHandle)
	Run ADC continuously into local ping/pong buffer.
void	AbortCapture (void)
	Aborts a continuous capture cycle.
unsigned int	SampleRateHz (void)

Static Protected Member Functions
static void	DMA_Channel_Handler (int anTcc)
	Handle a TCC complete code from an ongoing transfer.

Protected Attributes
int	mnDevNum
	the McBSP running port number
MCBSP_Handle	mhMcBSPHandle
	CSL Handle to McBSP.
EDMA_Handle	mhEDMA
	CSL handle to base DMA table.
EDMA_Handle	mhEDMA_pong
	CSL handle to pong transfer.
EDMA_Handle	mhEDMA_ping
	CSL handle to ping transfer.
int	mnTcc
	our allocated transfer complete code
int	mnNumChannels
	number of channels collected during operation
SEM_Handle	mhPingPong
	semaphore handle to post for continous capture
volatile bool	mbAbortCapture
	true when a continuous capture abort is pending
volatile bool	mbCCaptureRunning
	true when a continuous capture is running
unsigned int	mnSampleRateHz
	our sampling rate

Static Protected Attributes
static tsTccMap	maTccMap [_MCBSP_PORT_CNT]
static int	mnNumOpenedMcBsps = 0

---

Detailed Description

Instances of this class create an interface to an ADS1278 24-bit analog to digital converter.

See also:

tcDspAdc1278 Page

---

Constructor & Destructor Documentation

tcDspAdc1278::tcDspAdc1278	(	int	mnMcBSPDevNum,
		unsigned int	anSCLKFreq_Hz,
		unsigned int	anFSample_Hz,
		int	anNumChannels
	)

This constructor is used to open a tcDspAdc1278 interface with the the specified settings (optional).

Parameters:

[in]	mnMcBSPDevNum	McBDSP Number as defined by CSL (MCBSP_DEV0 or MCBSP_DEV1 for MityDSP/XM) (CSL_MCBSP_0 or CSL_MCBSP_1 for MityDSP-PRO)
[in]	anSCLKFreq_Hz	Desired chip SCLK rate, in Hz
[in]	anFSample_Hz	Desired sample rate (per channel), in Hz
[in]	anNumChannels	Number of channels read per sample (minimum 1)

Note:

The SCLK rate should be evenly divisible by the ADC CLK rate.

The anFSample_Hz must be at least 256 ADC CLKs.

The SCLK should be evenly divisible by the anFSample_Hz rate

An example to accomplish a 20,000 Hz sampling rate would include:

• Running the ADC clock at 25 MHz.
• Running the SCLK at 25 MHz
• Running the Sampling Rate at 20,000 Hz

Returns:

None.

See also:

DspAdc1278.h

tcDspAdc1278::~tcDspAdc1278

(

)

Default destructor.

Returns:

None.

---

Member Function Documentation

unsigned int tcDspAdc1278::GetSamples	(	int *	apBuffer,
		int	anNumWords,
		SEM_Handle	ahSemHandle
	)

Get a sample from the ADC.

Parameters:

[in]	apBuffer	Buffer to store the samples
[in]	anNumWords	number of ADC samples to store into buffer, must be less than 65536 and greater than 0.
[in]	ahSemHandle	Semaphore Handle that will be posted with transfer completes, if the Handle is NULL, then the operation will block until the transfer completes

Note:

it would make sense to have the anNumWords evenly divisible by the anNumChannels specified in the constructor.

Returns:

the number of samples scheduled for a read

See also:

DspAdc1278.h

int tcDspAdc1278::ContinuousCapture	(	int *	apBuffer[2],
		int	anWordsPerBuffer,
		SEM_Handle	ahSemHandle
	)

Run ADC continuously into local ping/pong buffer.

Parameters:

[in]	apBuffer	Buffers to store the samples (ping/pong style)
[in]	anWordsPerBuffer	number of ADC samples to store into each buffer, must be less than 65536 and greater than 0.
[in]	ahSemHandle	semaphore to post when ping/pong flip occurs

Note:

it would make sense to have the anNumWords evenly divisible by the anNumChannels specified in the constructor.

Returns:

the value read from the ADC

See also:

DspAdc1278.h

void tcDspAdc1278::AbortCapture

(

void

)

Aborts a continuous capture cycle.

Should be called to terminate a continuous capture operation. Returns when DMA engine has beed disabled.

See also:

DspAdc1278.h

unsigned int MityDSP::tcDspAdc1278::SampleRateHz ( void  )

inline

void tcDspAdc1278::DMA_Channel_Handler ( int  anTcc )

staticprotected

Handle a TCC complete code from an ongoing transfer.

Parameters:

[in]

anTcc

transfer complete code from ISR handler

See also:

DspAdc1278.h

---

Member Data Documentation

tcDspAdc1278::tsTccMap tcDspAdc1278::maTccMap

staticprotected

int tcDspAdc1278::mnNumOpenedMcBsps = 0

staticprotected

int MityDSP::tcDspAdc1278::mnDevNum

protected

the McBSP running port number

MCBSP_Handle MityDSP::tcDspAdc1278::mhMcBSPHandle

protected

CSL Handle to McBSP.

EDMA_Handle MityDSP::tcDspAdc1278::mhEDMA

protected

CSL handle to base DMA table.

EDMA_Handle MityDSP::tcDspAdc1278::mhEDMA_pong

protected

CSL handle to pong transfer.

EDMA_Handle MityDSP::tcDspAdc1278::mhEDMA_ping

protected

CSL handle to ping transfer.

int MityDSP::tcDspAdc1278::mnTcc

protected

our allocated transfer complete code

int MityDSP::tcDspAdc1278::mnNumChannels

protected

number of channels collected during operation

SEM_Handle MityDSP::tcDspAdc1278::mhPingPong

protected

semaphore handle to post for continous capture

volatile bool MityDSP::tcDspAdc1278::mbAbortCapture

protected

true when a continuous capture abort is pending

volatile bool MityDSP::tcDspAdc1278::mbCCaptureRunning

protected

true when a continuous capture is running

unsigned int MityDSP::tcDspAdc1278::mnSampleRateHz

protected

our sampling rate