Hi Everyone Maybe previous a question to application external memory has confused, let me repost sample question about stack of instructions. The assembler code is push register R0,R1 onto stack and pop register R0,R1from stack. So how to write a C51 program like this function or have any instructions? PUSH 0 ; register R0 PUSH 1 ; register R1 . . . . POP 1 ; register R0 POP 0 ; register R1