6 Mbps on SPI.

[Eric Provost]

Hello. I'm working with the nrf52 with s132 loaded. There is a way to have a 6Mbps on the SPI ? I try the value 0x60000000 but this do not work. Thanks. Eric Provost.

[Håkon Alseth]

Hi,

Anything over 4 MHz will be greatly influenced by pad and trace capacitance, so I would highly recommend checking the rise and fall time of your signal. You can generate a 5.3 MHz (16M / 3) signal by setting FREQUENCY = 0x48000000;, but not a 6 MHz frequency.

Cheers, Håkon

[Tim D]

Thanks for the answer. I was assuming you were based off a 32MHz clock, this explains things. When you say QSPI, do you mean QDEC? I'm not seeing a QSPI peripheral in the datasheet.

Also, we have had good luck with the 8MHz SPI. But we have custom designs which are very well done.

I suggest on the nRF53 or next rev of nRF52 that a faster SPI bus is used and you consider a DMA model that allows longer transactions and remove the delay between DMA transactions.