Assembly language instruction and debug command character

mov and add instructions

Assembly Instructions	Control what the CPU is doing	Formal syntax description
mov ax, 18	Send 18 to Ax	(AX) =18
mov Ah, 78	Send 78 to AH	(AH) =78
Add Ax, 8	Add 8 to the value in AX	(AX) = (AX) +8
MOV ax, bx	Send data in BX to AX	(AX) = (BX)
Add ax, BX	Add ax, BX content, results into Microsoft Dynamics AX	(AX) = (AX) + (BX)

• Description: Assembly instructions are case-insensitive; two operands must be in the same number of digits.

debug Command? R command: View, change the contents of the CPU register? d Command: Displays the contents of a piece of memory area in 16 binary format  ? e command: Overwrite the contents in memory? A command: Write a machine instruction &nbsp in memory in the format of assembly instruction; U command: Translate in-memory machine instructions into assembly instructions? T command: Execute a machine instruction  ? G Command: Executes to the specified position (breakpoint), such as "G cs:0012";? P Command: Execute subroutine call, loop, interrupt, repeat string operation and so on, stop at the next instruction.  ? Q command: Exit Debug Description:? The data entered or displayed in debug is in hexadecimal form; The debug command is a single letter, the case of commands and parameters can be mixed input; When a syntax error occurs in the command, "^error" is displayed in the error location; Before executing an instruction with the T command, make sure it is valid. Invalid instructions can cause deadlock in the processor, debug cannot respond, and even reboot the system.                                                                                                                        mov/add/sub directive (        )                                                                 function: Transmit, accumulate, reduce.                                                                          format: two operands.

Number of Operations 1	Number of Operations 2	Example
Register	Immediate number	mov ax, 1000H
Segment Register	Register	MOV ds, ax
Register	Register	Add bx, ax
Register	Memory Unit	Sub CX, [0]
Memory Unit	Register	mov [0], AL
Register	Segment Register	MOV bx, DS
Memory Unit	Segment Register	mov [0], DS
Segment Register	Memory Unit	mov ds, [0]
......	......	......

Inc Directive (INC) format: inc operand? Function: Add the value of the operand by 1? Description: The operand can be a register, or the memory unit Dec instruction (dec)? format: Dec operand? Function: Reduce the value of the operand by 1? Description: The operand can be a register, or it can be a memory unit • What are the key features of looping using the Loop command? Number of cycles in CX; The address identified in the loop instruction is preceded by the instruction, and the program segment to be executed is written in the middle of the label and loop instruction; Loop Loop Program Framework

MOV cx, number of cycles

S: loop-executed program segments

......

Loop s

Assembly language instruction and debug command character