I wanted to use the ADXL355 with an external clock for more precision. I've already set the EXT_SYNC and the EXT_CLK registers. I'm using a clock at 250kHz and I expect to be measuring at 976.6Hz (as the datasheet says, 976.6x64x4 = 250000) but it's sampling at 244Hz, four times slower than expected. The ODR is set to 1kHz.
Also, if I connect a 976.6Hz square signal to the sync pin, the sensor stops measuring, so I've disconnected it.
Anyone knows why does this happen?