Question

PUSH B which addressing mode

Answer 1

Push B is one address instruction becoz to push value onto stack we need the address of top of the stack so due to this adddress it is again one address instruction only !

Comments

It is one address, but addressing mode refers to how the operand is obtained- like direct, indirect, immediate, indexed.

---

Yes sir. Push instruction uses direct addressing mode but it is invalid to say like PUSH A

THERE SHOULD BE ADDRESS MENTIONED AFTER OPCODE IN CASE OF DIRECT ADDRESSING MODE

Ex : push 03

WHERE O3 TELLS PUSH IN REGISTER R3.

---

It is indirect addressing mode

This is not direct we are not mentioning address here

PUSH  Push register pair onto stack

now PUSH B will copy the contents of register pair BC into the stack in given order

1)The stack pointer is decremented and the contents of B are copied into that location so address is found by stack pointer which is pointing so some location in stack (so indirectly memory access one memoy access)

2) The stack pointer is decremented again and the contents of C  are copied into that location