Hello Asok Sankar Rudra,
Here is the way I compiled clock.c on my computer which is running Windows XP. I have SDCC installed in the following directory c:program Filessdcc.

1. c: cdclockexample
2. c:progra~1sdccbinsdcc clock.c
3. c:progra~1sdccbinpackihx clock.ihx > clock.hex
4. c:progra~1sdccbinhex2bin clock.hex 

That's it.
Regards,
Charles Bannister