In our product board, the product which is not started normally appeared rarely.
When the phenomenon occurs, ADXL345 is on SPI communication and does not return a response.
It seems that it had the ramp up problem of a power supply as a result of investigation.
A power supply waveform is as an attached file.
The leak current which goes via another Device-I/O from the system power was raising the power rail of ADXL345.
And then when removing the leak current, all the our product boards work normally.
A description is not in ADXL345 data sheet about the start up time for VDDIO, Vs and etc.
If there are restrictions and some notes, please let me know.
Also generally it we wish to know it even if.