nRF51822 SPI clock frequencyhttps://devzone.nordicsemi.com/f/nordic-q-a/2891/nrf51822-spi-clock-frequencyI was wondering what the SPI clock frequencies were in Hz. thanks, Matten-USTelligent Community 13Tue, 24 Jun 2014 07:07:13 GMTRE: nRF51822 SPI clock frequencyhttps://devzone.nordicsemi.com/thread/11018?ContentTypeID=1Tue, 24 Jun 2014 07:07:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3545ceaf-5b26-4fb3-99dd-103e6b02b839Stefan Birnir Sverrisson<p>Hi Matt</p> <p>The selection of frequencies for the SPI can be seen in section 25.2.8 in the <a href="https://www.nordicsemi.com/eng/nordic/Products/nRF51822/nRF51-RM/20337">nRF51 Series Reference Manual v2.1</a>, selectable from 125kbps to 8Mbps. If the selected SPI speed is 8Mbps, it means that the SPI clock frequency on a configured CLK pin is 8MHz.</p> <p><strong>Update 10.11.2015</strong><br /> The 8MHz maximum bit rate in the nRF51 Reference Manual version 2.1 and version 3.0 is misleading. The maximum SPI master bit rate is 4MHz as stated in the nRF51822/nRF51422 PS version 3.1, section 8.9. 8MHz bit rate is out of specification.</p><div style="clear:both;"></div>