Sriharsha,

The justification issue raises it's head when the converter data word does not match the interface word size. For example 12 bit data being presented to a 16 bit word interface (even when it is byte at a time).

As previously noted, left justification ensures the sign bit it located in the Most Significant Bit. This can "ease" math processing of the data value.

Right justification is just as "valid" but if the sign is not extended to the MSB, someone, most probably you, will sooner or later have to rotate the word.

Right justification can "ease" some hardware interfacing but i have yet to ever use it.

Instead, as was noted earlier, Left justification allowed the construction of 16 bit processing that was just as applicable for 12 bit data.

regards,
p