about nRF52840's qspi frequency of clock

[visionwang]

Problem1: I measured the clock of  nRF52840's qspi, is it ok? Frequency is 32Mhz.

Problem2: When I changed the clock frequency of nRF52840's qspi, but  it didn't change.   And I tested it in  PCA10056 development board(  demo is nRF5_SDK_15.3.0_59ac345\examples\peripheral\qspi), the clock frequency didn't change either.

The code is as follows:

// <o> NRFX_QSPI_CONFIG_FREQUENCY - Frequency divider.

// <0=> 32MHz/1
// <1=> 32MHz/2
// <2=> 32MHz/3
// <3=> 32MHz/4
// <4=> 32MHz/5
// <5=> 32MHz/6
// <6=> 32MHz/7
// <7=> 32MHz/8
// <8=> 32MHz/9
// <9=> 32MHz/10
// <10=> 32MHz/11
// <11=> 32MHz/12
// <12=> 32MHz/13
// <13=> 32MHz/14
// <14=> 32MHz/15
// <15=> 32MHz/16

#ifndef NRFX_QSPI_CONFIG_FREQUENCY
#define NRFX_QSPI_CONFIG_FREQUENCY 15
#endif

[haakonsh]

Something is terribly wrong. Your clock signal is heavily capacitively loaded, you need to investigate the source of this capacitance. The signal is also 37MHz instead of 32MHz so I don't really know what signal your actually measuring. 
 

#define NRFX_QSPI_CONFIG_FREQUENCY 15

 Is this config actually used by your code? 

[visionwang]

now clock wave is ok,but clock's frequency is still not changed by code; I am sure the config is used;

[haakonsh]

visionwang said:

I am sure the config is used;

 Show me.