On take off, one selects RTO (Rejected Take Off) setting on the autobrake system, so that if after 80kts on the take off run, take off is aborted, as soon as the throttles are pulled back, the maximum braking is automatically applied.
Also the spolers can be armed so that they deploy at the same time in an aborted take off - Also spoliers can be armed so that brakes are automatically applied on main bogie wheel touchdown when landing.
The autobrakes also have setting 1,2,3,4, MAX, for automatic braking on landing, higher the setting the greater the braking force. So for instance if one needs to slow down quickly in order to vacate the runway at a certain taxiway - on the approach, or descent a higher autobrake setting would be selected. However one would need to take into consideration when the plane will next be flying, because higher automatic braking makes the brakes VERY hot - and may take an hour or two to cool down to a temperature that would be permissible with which to fly again.
Hope that answers your question.