In its simplest, single-state configuration, the SCT operates as an event controlled one- or bidirectional counter. Events can be configured to be counter match events, an input or output level, transitions on an input or output pin, or a combination of match and input/output behavior. In response to an event, the SCT output or outputs can transition, or the SCT can perform other actions such as creating an interrupt or starting, stopping, or resetting the counter. Multiple simultaneous actions are allowed for each event. Furthermore, any number of events can trigger one specific action of the SCT.
An action or multiple actions of the SCT uniquely define an event. A state is defined by which events are enabled to trigger an SCT action or actions in any stage of the counter. Events not selected for this state are ignored.
In a multi-state configuration, states change in response to events. A state change is an additional action that the SCT can perform when the event occurs. When an event is configured to change the state, the new state defines a new set of events resulting in different actions of the SCT. Through multiple cycles of the counter, events can change the state multiple times and thus create a large variety of event controlled transitions on the SCT outputs and/or interrupts.
Once configured, the SCT can run continuously without software intervention and can generate multiple output patterns entirely under the control of events.
© NXP N.V. 2014. All rights reserved.