What are the features of the Intel 8051 architecture that allow it to successfully act as a microcontroller? Hypothetically can the general-purpose 8-bit architecture like Intel 8080 do everything the 8051 can? If not, why?
For example, can the bit addressable IO ports of the 8051 be emulated by using bitmasking with the
OUT commands of the 8080? Or are the IO ports of the 8051 intrinsically different from the databus of an 8080? For example modern microcontrollers often have dedicated circuitry for the IO ports, did the 8051 have to do this to become a microcontroller?
Assume that the memory, UART, and timer/counter of the 8051 are made external. That is they are interfaced with as external devices as they would be in the 8080.