Hi Yogesh,
Its not completely accurate to say there is no deep sleep. You can still invoke both sleep and deep sleep. All the internal IO are taken care of in both sleep modes. Deep sleep additionally handles external IO. For a more detailed explanation, see the ‘Deepsleep functionality change’ explanation found at the following link:
https://developer.mbed.org/platforms/MTS-mDot-F411/
Kind regards,
Leon