Question

I want an ARM7 Assembly code that checks if a number is Even or Odd. If the number is
even, register R3 should contain 1, otherwise contain 0.


could somebody help me ?!

Answer 1

for even number the least significant bit(LSB) is 0 zero
for odd number the least significant bit(LSB) is 1 one

Algorithm:

-->Take any number
-->Make logical AND operation of that number with 1

Suppose you have this 10 bit number 0000000011 which is 3 in decimal.

Make it AND with 0000000001

so it becomes

0000000011
AND
0000000001
----------------
0000000001 ----> result
-->Put this result in any register (say R1) and place a check on it

The check should be like this:

if R1 = 1
then R3 = 0
else R3 = 1

you are done

Remember:
the result obtained by ANDING 0000000001 with any odd number will always be 0000000001 and by ANDING 0000000001 with even number will always result in 0000000000.

now i have told you the algorithm. make the programme its easy but if you feel any problem. just post the problem.