The reference manula says i can configure the STM32 GPIO as either Input pull-up or as Input-pull-down.
But i do not see any register which configures this. Can anybody clarify this.
Regards, Jawaad
The whole point of the Standard Peripheral Library is to save you having to worry about the details of individual registers.
I would suggest that you start by using the Standard Peripheral Library - so that you can gain an understanding of how the chip as a whole works.
Once you have that basic understanding, then you can start delving into the inner details of the registers if you still find it necessary...
Note that the Standard Peripheral Library is provided as source code - so you can see what registers it uses, and how...