Q
Yes, Topfly's description is correct and what is of most interest (for me, at least) is that the throttle HOLD activation is on IAS, not G/S. The point being, for instance, if you do a rolling take-off on a strong wind day, if the throttle servo is a bit on the sluggish side, you could well end up with throttle HOLD at less than reference thrust. Both my ex-company's SOPs had a requirement for a thrust check at the HOLD annunciation to cover the possibility and, were it necessary, thrust could then be manually trimmed up BEFORE reaching 80kts.
Cheers