Sub subtract instruction, Electrical Engineering

SUB Subtract Instruction

This  instruction  is used to  subtract the contents of any  register  or memory location from  the contents of  accumulator. There are two  formats as follows:

a.Subtract the contents of Register The  contents of  register R are subtracted  from the contents of accumulator and  result of operation is  stored in the accumulator. Here register R  may be any  one  of the A, B, C,D, E,H or L registers.

SUBR                   ( A- A - R)

Flags : All  flags  are modified according to the results.

As we have already  discussed in chapter 1 that the subtraction is done  using 2 s  complement  method in microprocessor.  Followings  steps are followed  by the  8085 microprocessor while performing  subtract operations.

 Step1.  Converts subtrahend ( the  number to  be subtracted) into its 1 s complement form.

 Steps2.  Adds 1 to  the 1 complements  form to  obtain 2  complement  form the  subtrahend.

 Step3.  Adds 2 complements  to the minuend ( the  contents of the accumulator).

 Step 4.  Complements  the carry  flag.

Posted Date: 4/4/2013 7:06:46 AM | Location : United States







Related Discussions:- Sub subtract instruction, Assignment Help, Ask Question on Sub subtract instruction, Get Answer, Expert's Help, Sub subtract instruction Discussions

Write discussion on Sub subtract instruction
Your posts are moderated
Related Questions

A 15kVA has a turns ratio 1:10. If the voltage applied is 13.8kV and the applied load is 20+j6. Find the current in the secondary winding and the active and reactive power consumed

What is Capacitor -  A capacitor is an electrical device that is used to kept electrical energy.   -  The unit of capacitance is Farad. The symbol of capacitance is C.

Q. What are the advantages of an RC coupling over a direct coupling? Draw a basic Rc coupling network and explain. Figure -RC-coupled transistor amplifier The network

Q. For the low-pass filter configuration of Figure, with R i = R f = 1M, calculate C f such that the 3-dB point is at 1 kHz.

Why does digital signal processing require specialized hardware? A) It needs to perform analog as well as digital functions. B) General-purpose microprocessors cannot perfor

what are the limitations of superposition theroem

Thermal noise This is the most significant noise in an ampli?er. It is produced by random movements of electrons in the resistors. This is caused by the ?uctuations in the volt

i want to prodused domestic power factor correction like industial