regarding 8051 microcontroller

[rajesh6821]

can somebody explain me how port0 of 8051 microcontroller has internal pullups when we access the external memory as it does not have internal pullups during normal operation compared to other ports.

 

[mishra12]

Port 0 is an 8-bit open drain bi-directional I/O port. As an
output port, each pin can sink eight TTL inputs. When 1s
are written to port 0 pins, the pins can be used as highimpedance
inputs.
Port 0 can also be configured to be the multiplexed loworder
address/data bus during accesses to external program
and data memory. In this mode, P0 has internal
pullups.
Port 0 also receives the code bytes during Flash programming
and outputs the code bytes during program
verification. External pullups are required during program
verification.