To be noticed by one; to enter one's awareness. In this usage, a noun or pronoun is used between "to" and "attention." Once the employee's complaint of mistreatment came to my attention, I knew I had to address it right away.

Of military personnel, to stand at attention (which, in most cases, means looking forward and standing erect with one's arms at one's sides). When they heard the drill sergeant's call, the troops abruptly stopped marching and came to attention.