Advanced Embedded Systems Interview Question:

Explain which 2 ports combine to form the 16 bit address for external memory access?

Submitted by: Muhammad

☛ Port0 and port2 together form the 16 bit address for external memory.
☛ Port0 uses pins 32 to 39 of 8051 to give the lower address bits(AD0-AD7)
☛ Port2 uses pins 21 to 28 of 8051 to give the higher address bits(A8-A15)
☛ This 16 bit address is used to access external memory if attached.
☛ When connected to external memory they cannot be used as input output ports.
Submitted by: Muhammad