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Altera_Forum
Honored Contributor I
742 Views

Need help with audio

I'm supposed to store incoming audio, and I found this code used working with the "meida computer". Exactely where is the incoming data stored? Here is the code: 

 

 

 

A fragment of C code that uses the audio port is shown in Figure 28. The code checks to see when the depth of either 

the left or right Read FIFO has exceeded 75% full, and then moves the data from these FIFOs into a memory buffer. 

This code is part of a larger program that is distributed as part of the Altera Monitor Program. The source code can 

be found under the heading sample programs, and is identified by the name Media. 

 

 

volatile int * audio_ptr = (int *) 0x10003040; // audio port address 

int fifospace, int buffer_index = 0; 

int left_buffer[BUF_SIZE]; 

int right_buffer[BUF_SIZE]; 

. . . 

fifospace = *(audio_ptr + 1); // read the audio port fifospace register 

if ( (fifospace & 0x000000FF) > 96) // check RARC, for È 75% full 

/* store data until the audio-in FIFO is empty or the memory buffer is full */ 

while ( (fifospace & 0x000000FF) && (buffer_index < BUF_SIZE) ) 

left_buffer[buffer_index] = *(audio_ptr + 2); //Leftdata 

right_buffer[buffer_index] = *(audio_ptr + 3); //Rightdata 

++buffer_index; 

fifospace = *(audio_ptr + 1); // read the audio port fifospace register 

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Altera_Forum
Honored Contributor I
17 Views

Obviously in left_buffer and right_buffer, which can be expected to exist in NIOS RAM space.

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