A block of 16-bit stereo audio data having the size of 4551792 bytes is transferred via I2S interface configured in DMA mode with 16-bit data width and DMA interrupts enabled. The sampling frequency is 44.1 kHz. Determine the maximum amount of data (total number of samples) per DMA transfer to implement playback so that all DMA transfers have the same size. Determine the time interval between DMA Transfer Complete Interrupts.
To determine the maximum amount of data per DMA transfer, we first need to calculate the size of each sample.
Since the audio data is 16-bit stereo, each sample contains 2 bytes (16 bits x 2 channels).
So, the total number of samples in the block of audio data can be calculated as follows:
Total number of samples = Total size of audio data / Size of each sample
Total number of samples = 4551792 bytes / (2 bytes/sample)
Total number of samples = 2275896 samples
Now, we need to determine the maximum amount of data per DMA transfer so that all transfers have the same size. To achieve this, we need to find the greatest common divisor (GCD) of the total number of samples and the maximum transfer size supported by the DMA controller.
The maximum transfer size for a 16-bit data width DMA controller is 65535 bytes.
Therefore, the maximum amount of data per DMA transfer is the GCD of 2275896 and 65535, which is 65535.
So, each DMA transfer will have 65535 bytes of audio data, which corresponds to 32767 stereo samples.
To determine the time interval between DMA Transfer Complete Interrupts, we need to consider the sampling frequency and the number of samples per transfer.
Time interval between DMA Transfer Complete Interrupts = Number of samples per transfer / Sampling frequency
Time interval = 32767 samples / 44100 samples/sec
Time interval = 0.742 seconds
Therefore, the time interval between DMA Transfer Complete Interrupts is approximately 0.742 seconds.