Purchase Solution

An 8086 subroutine that multiplies two signed 16-bit values together without using the mul instruction.

Not what you're looking for?

Ask Custom Question

I'm trying to teach myself 8086 assembly. I need an example of how to use an assembly language subroutine, using only 16-bit registers, to multiply two signed 16-bit values together without using the mul instruction. My book gives the example below but doesn't give a clear explanation of how to use it:

a) clear the a register
b) place the multiplicand in the D register
c) do the next step 4 times (multiplying 4 bit numbers). if the left most bit of the D
register is a 1 then shift both registers to the left one bit, add the multiplier to the
A register, else shift both registers to the left one bit.

Purchase this Solution
Solution Preview

Please find the attached file as the solution to your problem.

Thanks and regards.

UPDATE FROM OTA:
The problem can be solved as,

first load two numbers in two different registers. if both the registers are of 16 bit then the result should be stored in a 32 bit register.

The concept of loading the values is same as in multi precision multiplication.

In case 32 bit registers, first we take the lower half(16 bit) and multiply it with the lower half of the ...

Purchase this Solution
Free BrainMass Quizzes
Basic UNIX commands

Use this quiz to check your knowledge of a few common UNIX commands. The quiz covers some of the most essential UNIX commands and their basic usage. If you can pass this quiz then you are clearly on your way to becoming an effective UNIX command line user.

Word 2010: Tables

Have you never worked with Tables in Word 2010? Maybe it has been a while since you have used a Table in Word and you need to brush up on your skills. Several keywords and popular options are discussed as you go through this quiz.

Word 2010: Table of Contents

Ever wondered where a Table of Contents in a Word document comes from? Maybe you need a refresher on the topic? This quiz will remind you of the keywords and options used when working with a T.O.C. in Word 2010.

Javscript Basics

Quiz on basics of javascript programming language.

Excel Introductory Quiz

This quiz tests your knowledge of basics of MS-Excel.

View More Free Quizzes
Related BrainMass Solutions

  • Motorola MC68000 Microprocessor Unit (MPU) Programming

    BN LOOP IF RESULT OF SUBTRACTION IS NON-ZERO, TRANSFER PROGRAM CONTROL TO THE LABEL LOOP. Note that this logic is entirely based on the instructions given in your specification, and does not use any instruction outside that.

  • The 8086 Family Architecture

    The 8086 Family Architecture is examined.

  • Data Conversion (8-bits to decimal)

    Q5 )without changing their values convert the following 2's complement binary numbers into 8-bit 2's complement numbers.

  • Comparing Address Machines

    In 2 address machine, each arithmetic instruction takes 4 access same as in 3 address machine , in addition, we have the load instructions that requires 3 accesses thus it takes total 20+9=29 memory accesses 1 Address mode X=(A+B*C)/D-E*F LOAD

  • ARC Subroutine that Performs a Swap Operation

    The solution writes an ARC subroutine that performs a swap operation on the 32-bit operands x=25 y=50 which are stored in memory.

  • Signed number representations

    Numbers with suffix B denote binary values, and numbers without any suffix denote decimal values. a.

  • Proof about determinants

    Prove the proposition without using Cofactors/Cramer's rule.) See Attached Please see the attachment. Proof: We should use the following properties of determinant. 1. Switching two rows or columns changes the sign. 2.

  • Require assistance with homework

    12 for the address 16-bit accumulator (AC) 16-bit instruction register (IR) 16-bit memory buffer register (MBR) 12-bit program counter (PC) 12-bit memory address register (MAR) 8-bit input register 8-bit output register What does the following

  • Logic Circuits

    A certain register used to store signed binary numbers provides a 16-bit output. Determine the range of register output values and how many different values the register capable of containing. 8.

View More Related Solutions