Functions
int	getblocksize (void)
	Return the number of samples that the user should expect to process per block. More...

void	setblocksize (uint32_t blksiz)
	Set the number of samples that the user should expect to process per block. More...

void	getblock (float *working)
	Request a block of data from the ADC sample stream. More...

void	getblockstereo (float chan1, float chan2)
	Request a block of data from the two ADC sample streams (Stereo input case) More...

void	putblock (float *working)
	Send a buffer of data to the DAC output stream. More...

void	putblockstereo (float chan1, float chan2)
	Send two buffers of data to the DACs for stereo output. More...

Detailed Description

Function Documentation

void getblock ( float * working )

Request a block of data from the ADC sample stream.

For one input channel (MONO_IN), getblock() is called by the user to request the next input data block. getblock() will wait until the ADC/DMA completes filling the requested block of samples. The binary data is then converted to float values and returned to the user.

Output samples will range from -1.0 to +1.0 to cover the range of the ADC input voltages. The converter is a 12-bit device, so the resolution of the output samples is roughly 2/4096 = 0.000488.

Assuming the original voltage range of the ADC is 0 to 3.0 volts, the conversion between the returned sample value and the input voltage is: Vin = 1.5 + (sample*1.5). (A zero sample value indicates the ADC is mid-scale, at 1.5 volts) For a 0-3 V ADC range, the ADC resolution is 3/4096 = 732 uV.

Returns: On return, the memory block pointed to by working will be filled with the requested data block.

Attention: The user is responsible for allocating enough memory to hold the requested array of float values. The number of samples required may be obtained by calling getblocksize()

See also: getblocksize(), getblockstereo()

Parameters

[in,out] working pointer to an array of floats (large enough to hold one buffer)

Definition at line 103 of file sample486.c.

int getblocksize ( void )

Return the number of samples that the user should expect to process per block.

Users should call getblocksize() once to determine the required number of samples which must be handled on each call to getblock() or getblockstereo(). Typically, the result is used to allocate required memory to handle the data

Returns: The number of ADC samples supplied per data request

Definition at line 59 of file sample486.c.

void getblockstereo	(	float *	chan1,
		float *	chan2
	)

Request a block of data from the two ADC sample streams (Stereo input case)

For two input channel (STEREO_IN), getblockstero() is called by the user to request the next input data blocks. getblockstereo() will wait until the ADCs/DMA completes filling the requested block of samples. The binary data is then converted to float values and returned to the user.

Output samples will range from -1.0 to +1.0 to cover the range of the ADC input voltages. The converter is a 12-bit device, so the resolution of the output samples is roughly 2/4096 = 0.000488.

Assuming the original voltage range of the ADC is 0 to 3.0 volts, the conversion between the returned sample value and the input voltage is: Vin = 1.5 + (sample*1.5). (A zero sample value indicates the ADC is mid-scale, at 1.5 volts) For a 0-3 V ADC range, the ADC resolution is 3/4096 = 732 uV.

Returns: On return, the memory blocks pointed to by chan1 and chan2 will be filled with the requested data blocks. Samples are normalized to range from -1.0 to 1.0 to cover the entire range of the ADC.

Attention: The user is responsible for allocating enough memory to hold the requested arrays of float values. The number of samples required for each array may be obtained by calling getblocksize()

See also: getblocksize(), getblockstereo()

Parameters

[in,out]	chan1	pointer to an array of floats for the main ADC channel
[in,out]	chan2	pointer to an array of floats for the stereo ADC channel

Definition at line 182 of file sample486.c.

void putblock ( float * working )

Send a buffer of data to the DAC output stream.

For one output stream (MONO_OUT), putblock() is called by the user when they've finished processing a block of data and are ready to stream the data to the DAC output. Samples passed to putblock() are assumed to range from -1.0 to 1.0 to cover the entire output range of the DAC.

Attention: The number of output samples required can be determined by calling getblocksize()

Parameters

[in] working Array of output samples

Definition at line 143 of file sample486.c.

void putblockstereo	(	float *	chan1,
		float *	chan2
	)

Send two buffers of data to the DACs for stereo output.

For two output streams (STEREO_OUT), putblockstereo() is called by the user when they've finished processing a block of data and are ready to stream the data to the DACs. Samples passed to putblock() are assumed to range from -1.0 to 1.0 to cover the entire output range of the DAC.

Attention: The number of output samples required can be determined by calling getblocksize()

Parameters

[in]	chan1	Array of output samples for the main output channel
[in]	chan2	Array of output samples for the stereo output channel

Definition at line 158 of file sample486.c.

void setblocksize ( uint32_t blksiz )

Set the number of samples that the user should expect to process per block.

setblocksize() may be called before calling initialize() to specify the number of samples which should be delivered to the user on each call to getblock() or getblockstereo().

If setblocksize() is not called, the default block size of DEFAULT_BLOCKSIZE is used for data transfers. Using a smaller block size (down to a limit of one sample) can reduced the latency between the input and output stream, at the cost of some efficiency in handling the data.

Attention: setblocksize() must be called before calling initialize().

Parameters

blksiz Number of samples per block of ADC/DAC data processed

Definition at line 68 of file sample486.c.

Functions

Detailed Description

Function Documentation