Hi!
No, it isn't necesary. You can write the programms without comments. Assembler compiler or cpu, or you pc computer doesn't need the comments. 8052 cannot read your comments for better understanding what you really expecting from it ;o)
The comments are for you, but if you mean you don't need them - no problem. I need comments, but maybe you don't. After a year, looking on the programm I don't remember why this register is using like in this routine. But maybe you have super memory and you can remember. So don't use the comments.

Wish you happy programming!
Jacek

PS
Why are you asking about?