Two byte  Instructions

In these  instruction the first byte  specifies  the operations code  and the  second byte  specifies the operand. To identify  two byte  instructions one must  observe followings  things.

The instruction have 8 bit  data as their  operand  and have I n their  mnemonics for example MVI ADI, SUI  etc are two  byte  instructions ( but  not LXI as it  has 16 bit data as its  operand).

The  instructions  have 8 bit   port address  as their  operand e g IN and OUT  instructions.

Since  each memory  locations may  store  only byte  hence  two byte instructions  require two memory  locations to store  them  in memory.

Suppose  instruction MVI, A, 8 bit  data is to be stored  at memory  location  2000 H.  It will  be stored  as shown  below.