Since each sample is 2 bytes (16-bit stereo audio), the total number of samples in the block of data is 2275896.
To determine the maximum amount of data (total number of samples) per DMA transfer, we need to find a factor of 2275896 that will allow for equal size DMA transfers. One possible approach is to find the greatest common divisor (GCD) of 2275896 and the maximum transfer size allowed by the DMA controller.
However, assuming the DMA controller can handle the maximum data size of 65535 (maximum value for a 16-bit register), we can calculate the maximum number of samples per DMA transfer by dividing the total number of samples by 65535:
2275896 samples / 65535 samples per transfer = 34.75
This means that each DMA transfer can contain up to 65535 samples, and there will be a total of 35 transfers to cover the entire block of audio data.
To determine the time interval between DMA Transfer Complete Interrupts, we need to calculate the duration of each transfer.
Duration of each transfer = Number of samples per transfer / Sampling frequency
Duration of each transfer = 65535 samples / 44100 samples per second ≈ 1.485 seconds
Therefore, the time interval between DMA Transfer Complete Interrupts will be approximately 1.485 seconds.
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.
4551792 bytes / (2 bytes/sample) = 2275896 samples
3 answers
are you sure this is correct?
Let's reevaluate the calculations:
Given:
- Block size: 4551792 bytes
- Data width: 16-bit stereo audio (2 bytes per sample)
- Sampling frequency: 44.1 kHz
- DMA transfer size limit: 65535 samples
Calculating the number of total samples in the block:
Total samples = Block size / Data width = 4551792 bytes / 2 bytes per sample = 2275896 samples
Now, calculating the maximum number of samples per DMA transfer:
Maximum samples per DMA transfer = DMA transfer size limit = 65535 samples
Total number of DMA transfers required:
Total DMA transfers = Total samples / Maximum samples per DMA transfer = 2275896 samples / 65535 samples per transfer ≈ 34.73
So, each DMA transfer will have a maximum of 65535 samples, and a total of 35 transfers will be needed to cover all the audio data.
To determine the time interval between DMA Transfer Complete Interrupts:
Time interval per DMA transfer = Number of samples per transfer / Sampling frequency
Time interval per DMA transfer = 65535 samples / 44100 samples per second ≈ 1.484 seconds
Therefore, the correct time interval between DMA Transfer Complete Interrupts will be approximately 1.484 seconds.
Given:
- Block size: 4551792 bytes
- Data width: 16-bit stereo audio (2 bytes per sample)
- Sampling frequency: 44.1 kHz
- DMA transfer size limit: 65535 samples
Calculating the number of total samples in the block:
Total samples = Block size / Data width = 4551792 bytes / 2 bytes per sample = 2275896 samples
Now, calculating the maximum number of samples per DMA transfer:
Maximum samples per DMA transfer = DMA transfer size limit = 65535 samples
Total number of DMA transfers required:
Total DMA transfers = Total samples / Maximum samples per DMA transfer = 2275896 samples / 65535 samples per transfer ≈ 34.73
So, each DMA transfer will have a maximum of 65535 samples, and a total of 35 transfers will be needed to cover all the audio data.
To determine the time interval between DMA Transfer Complete Interrupts:
Time interval per DMA transfer = Number of samples per transfer / Sampling frequency
Time interval per DMA transfer = 65535 samples / 44100 samples per second ≈ 1.484 seconds
Therefore, the correct time interval between DMA Transfer Complete Interrupts will be approximately 1.484 seconds.
1 answer