51 Address bus (AB)

The address bus is unidirectional and is used to transfer address information. The address bus has a width of 16 bits, so the base external memory directly addresses 64K.

The bus width is 16 bits, "bit" is not bit or byte, and the bus's bit width refers to the number of bits of binary data that the bus can transmit at the same time, or the number of bits of the bus.

In general, if the address bus is n-bit, the addressable space is 2^n bit.

16-bit width: can be represented by the range 0000-FFFF

Addressing range: 2^16=65536BYTE=64KB

P0 Port when accessing external memory, the P0 port is both a true two-way data bus port and a 8-bit address port from the tick-out.

The 16-bit address bus is provided with a low 8-bit address (A0~A7) by the P0 port via the address latch, and the P2 port directly provides a high 8-bit address (A8~A15).

(KB, MB, GB commonly used K, M, G representation)

51 Address bus (AB)