Chaining Counter Timers

A feature of the Universal Timer module is the ability to chain two counter/timers into a single module. Setting the CHxyz bit in the TUCHAIN register will combine two instances of Universal Timers into a single bigger Timer module. When two Universal Timer modules are chained, one of them becomes the Main module, whereas the other becomes the Secondary module. The Main module forms the least significant segment of the combined counter/timer, whereas the Client module forms the most significant segment. Figure 1 shows the Main/Secondary configuration of the Chained Operational Model.

When operating in this configuration, control of the combined counter/timer is via the TUxyCON0, TUxyCON1, TUxyPS, TUxyCLK, TUxyERS and TUxyHLT registers of the Main module. The same registers of the Secondary module become defunct. The timer output, interrupts and DMA triggers for the combined timer/counter are generated by the Main module.

The TUxyTMR counter, TUxyCR capture, and TUxyPR period registers of both the Main and Secondary modules are combined respectively to provide higher-width register control for the combined counter/timer.

The timer chaining in this device is as follows:
Table 1. Timer Chaining
TUxy Instance Main/Secondary TUCHAIN Control Bit Chained Timer Size
TU16A (16-bit) Main (Least Significant Segment) CH16AB 32-bit
TU16B (16-bit) Secondary (Most Significant Segment)
Figure 1. Chained Operational Model