Determine the amount of memory buffer (in bytes) required for the duration of 2s of audio recording using DFSDM configuration data from question 1, if the audio samples are stored with 16-bit
resolution. Show all your work.
DFSDM clock divider D =57, oversampling ratio R = 64
We are given the DFSDM clock divider (D) and oversampling ratio (R) and need to calculate the audio sample rate, which is given by the following formula:
Data Rate = DFSDM_Clock / (D * R)
First of all, we need to find the DFSDM_Clock. The STM32L4 series has a maximum DFSDM clock of 36MHz.
DFSDM_Clock = 36MHz
D = 57
R = 64
Now we can plug these values into the formula:
Data Rate = 36MHz / (57 * 64)
Data Rate = 36,000,000Hz / 3648
Data Rate = 9866.565Hz
Now that we have the data rate, we can calculate the number of audio samples needed for 2 seconds.
Number of samples = Data Rate * Duration
Number of samples = 9866.565 * 2s
Number of samples = 19733.13
Since we have a 16-bit resolution, we can find the number of bytes required by multiplying the number of samples by 2 (two bytes per sample):
Memory Required (bytes) = 19733.13 * 2
Memory Required (bytes) = 39466.26
Since we can't have a fraction of a byte, we would round up to the nearest whole number, which is 39467 bytes. So, the amount of memory buffer required for the duration of 2 seconds of audio recording is 39467 bytes.