Rep instruction in 8086 example

Example: 8086 instructions Page 4 of 53. memory, immediate REG, immediate STC ; set CF = 1 It is a 16-bit Microprocessor having 20 address lines and16 data lines that provides up to 1MB storage. This chapter describes the instruction set mappings for the IA-32 Assembler processor. The 8086 allows you to subtract the ASCII codes for two decimal digits without masking the "3" in the upper nibble of each. The AAS instruction is then used to make sure the result is the correct unpacked BCD. ? Let AL = 00111001 (39H or ASCII 9), and BL = 00110101 (35H or ASCII 5) SUB AL, BL AL Complete 8086 instruction setQuick reference Some examples contain macros, so it is advisable to use Shift + F8 hot key to Step Over (to make macro code execute at maximum speed set step delay to zero) Example: ORG 100h LEA SI, a1 MOV CX, 5 REP LODSW ; finally there will be 555h in AX. Below is the full 8086/8088 instruction set of Intel (81 instructions total). Push an immediate byte/word value onto the stack. example These are register versions of the same instructions in AVX1. REP : Repeat Instruction Prefix This instruction is used as a prefix to other instructions, the instruction to which the REP prefix is provided, is Example : Write an instruction sequence to save the contents of the 8086's flags in memory location MEM1 and then reload the flags with the contents You can for example use it to translate index of food in menu into price for food, if your food index is 0..255 and price will fit into 8 bits too. In common applications you will hardly find any usage for xlat instruction. It's archaism from 8086 times, compiler will certainly not use it, and most of hand written Example : REP MOVSB STR1, STR2. Difference : inter segment call & intra segment call. Inter Segment jumps can transfer control to a instruction in a different code segment / Intra Segment jumps are always between instructions in the same code segment. Example 9.5. Write an 8086 assembly language program to multiply two 16-bit unsigned numbers to provide a 32-bit result. Assume that the two numbers Write a subroutine in 8086 assembly language which can be called by a main program inthe same code segment. The subroutine will multiply a Jump Instructions are used for changing the flow of execution of instructions in the processor. If we want jump to any instruction in between the code Syntax: JMP procedure_namememory_location Example: JMP short target. 2) Conditional Jumps. In these types of instructions, the processor must Instruction Set of 8086. — An instruction is a binary pattern designed inside a microprocessor to perform a — The entire group of instructions that a microprocessor supports is called Instruction Set. — REP (Repeat): — This is an instruction prefix. — It causes the repetition of the instruction Explain clearly with examples the following 8086 instructions. REP prefix XLAT IN and OUT MOV ADD AX, ES:[SI] PUSH. What are the contents of the data bus and the status of A0 and BHE when the following instructions are executed in 8086? a. CPU writes a byte 11 H at memory location Instructions for each family member, which include the 80386, 80486, Pentium, Pentium Pro, Pentium II, Pentium III, and Pentium 4 processors, are compared A complete listing of all 8086-Pentium 4 and Core2 instructions, including many example instructions and machine cod-ing in hexadecimal as Instructions for each family member, which include the 80386, 80486, Pentium, Pentium Pro, Pentium II, Pentium III, and Pentium 4 processors, are compared A complete listing of all 8086-Pentium 4 and Core2 instructions, including many example instructions and machine cod-ing in hexadecimal as Intro to Stack | Push | Pop in 8086 Assembly Language with examples.