The smallest metrical beat of யாப்பு, built by combining குறில்/நெடில்/ஒற்று letters. It comes in 2 kinds by length - a short beat and a long beat.

A poet composing a வெண்பா counts அசை on their fingers before writing a single word, since every சீர் down the line depends on getting this smallest unit exactly right.

நேரசை, நிரையசை.