https://devzone.nordicsemi.com/f/nordic-q-a/23127/twim-i2c-scl-clock-is-half-the-expected-frequencyOn nRF52, I see that 100 kHz gives a SCL period of 10 us which is correct but for 250 kHz, I get 8 us instead of expected 4 us. Similarly, for 400 kHz I only see 5 us instead of 2.5 us. These measurements are done on an oscilloscope. Any ideas whaten-USTelligent Community 13Thu, 29 Jun 2017 06:44:13 GMThttps://devzone.nordicsemi.com/thread/90972?ContentTypeID=1Thu, 29 Jun 2017 06:44:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:aeb9b0bf-0557-40fa-adcb-d7a049b56a7dMartinBL<p>Hi,</p> <p>Could it be related to the value of your <a href="https://devzone.nordicsemi.com/question/61466/does-nrf51-has-optional-internal-pullup-resistors-on-some-pins/">pull up resistors</a>?</p><div style="clear:both;"></div>