What is the maximum program memory capacity of 8051 Why?

The maximum program memory capacity of the 8051 microcontroller is 64 KB. This limitation arises from its 16-bit address bus, which allows it to address a maximum of (2^{16}) (or 65,536) memory locations. Each memory location corresponds to one byte, hence the 64 KB capacity for program memory. This design constraint is inherent to the architecture of the 8051.