nrf52832 Crystal frequency

[Eric]

The manual clearly states that the external HFXO should be 32MHz. However, if one would like to have precise 16kHz on the PDM and I2S interfaces a 32.768MHz crystal is required.

So, will things start to fail/degrade if I use a 32.768MHz crystal instead ?

[AmbystomaLabs]

You should review page 457 of the nRF52832 spec which discusses the 32MHz clock and the frequencies of the i2s port:

A RW MCKFREQ Master clock generator frequency. 32MDIV2 0x80000000 32 MHz / 2 = 16.0 MHz

32MDIV3 0x50000000 32 MHz / 3 = 10.6666667 MHz

32MDIV4 0x40000000 32 MHz / 4 = 8.0 MHz

32MDIV5 0x30000000 32 MHz / 5 = 6.4 MHz

32MDIV6 0x28000000 32 MHz / 6 = 5.3333333 MHz

32MDIV8 0x20000000 32 MHz / 8 = 4.0 MHz

32MDIV10 0x18000000 32 MHz / 10 = 3.2 MHz

32MDIV11 0x16000000 32 MHz / 11 = 2.9090909 MHz

32MDIV15 0x11000000 32 MHz / 15 = 2.1333333 MHz

32MDIV16 0x10000000 32 MHz / 16 = 2.0 MHz

32MDIV21 0x0C000000 32 MHz / 21 = 1.5238095

32MDIV23 0x0B000000 32 MHz / 23 = 1.3913043 MHz

32MDIV30 0x08800000 32 MHz / 30 = 1.0666667 MHz

32MDIV31 0x08400000 32 MHz / 31 = 1.0322581 MHz

32MDIV32 0x08000000 32 MHz / 32 = 1.0 MHz

32MDIV42 0x06000000 32 MHz / 42 = 0.7619048 MHz

32MDIV63 0x04100000 32 MHz / 63 = 0.5079365 MHz

32MDIV125 0x020C0000 32 MHz / 125 = 0.256 MHz