Bit-reverse a byte on 68HC12

Question

I\'m in a microprocessors class and we are using assembly language in Freescale CodeWarrior to program a 68HCS12 micro controller. Our assignment this week is to revers a by

Answer 1

For example, if you have in al the byte number the easiest way is

mov al, 10101110
mov ecx, 8

we put 8 in ecx for loop

mov ebx, 0 

In bl we will havee the result, we will make ebx, only to see what happens better

loop1:
sal al, 1;           

In carry flag now you have the last bit from left

rcr bl, 1;           

now you add in bl what you have in carry

loop loop1

and that's all