cwave.eu5.org
Also see: http://www.angelfire.com/dragon/letstry
cwave04 at yahoo dot com
Free Guestbook
My Guestbook

Last updated on Fri May 21 11:47:50 IST 2010.

Arithmetic

Incrementing

Next we shall learn about simple arithmetic. As usual a little lab session would help. The following command incremements ACC by 1. Notice that the SFR ACC is always refered to as A in assembly language (there does not seem to be any deep reason behind this convention!). 

inc A
Try it out.

You can of course try 

inc R4
or 

inc 5
The last command is like the C command RAM[5]++.
Lab session
Try the following. 

mov R0, #255
inc R0
Notice how R0 "rolls over" to 0. Also notice that this "rolling over" does not change anything else (for instance no "carry" bit is set).

Decrementing

The command dec is for decrementing, and is the opposite of inc. Try out the following to get a hang of it.
Lab session
Try the following. 

mov R0, #2
dec R0
Also try 

inc R0
inc R0
dec R0
Prev
© Arnab Chakraborty (2010)