No i asked in general.
i'm tring to understand how GPIO implemented in mcus & if also some mcu includes Hi-Z option in GPIO, so how it can be acheived? QUOTE]
Is this a college/university assignment i.e. is this your homework?
Either way, I think you need to do some fundamental digital electronics reading. Make sure you understand the TTL 'push-pull' logic output. From there you can read and understand open-drain and tri-state. Trying to teach you that here is not what the forum's aiming for.
Either way, the usual method to get a GPIO pin into high-impedance mode is to configure it as an input and ignore it in software.
However, if it's a true 8051 or similar, you configure a pin to be an input by writing a '1' to it's output register then leaving it alone. These MCUs implement 'quasi-bidirectional' GPIO pins which was a scheme that saved MCU logic gates by eliminating configuration registers etc back when every gate was precious.
Please do the reading, it's the best way. Good luck...