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.
The size of the block of 16-bit stereo audio data in bytes is 4551792 bytes. In stereo audio, each sample consists of 2 bytes (1 byte per channel), so the total number of samples in the block can be calculated as follows:
Total number of samples = 4551792 bytes / 2 bytes/sample = 2275896 samples
Since the DMA mode is configured with a 16-bit data width, the maximum amount of data per DMA transfer will be limited by the size of the DMA data register, which is typically 16 bits or 2 bytes. Therefore, the total number of samples per DMA transfer will be:
Total number of samples per DMA transfer = 2 bytes / 2 bytes/sample = 1 sample
The time interval between DMA Transfer Complete Interrupts can be calculated by dividing the total number of samples by the sampling frequency:
Time interval = Total number of samples / Sampling frequency
Time interval = 2275896 samples / 44100 samples per second
Time interval ≈ 51.57 seconds
Therefore, the maximum amount of data per DMA transfer to implement playback so that all DMA transfers have the same size is 1 sample, and the time interval between DMA Transfer Complete Interrupts is approximately 51.57 seconds.