Timer1 Operation

The Timer1 module is a 16-bit incrementing counter that is accessed through the TMRxH:TMRxL register pair. Writes to TMRxH or TMRxL directly update the counter.

When used with an internal clock source, the module is a timer and increments on every instruction cycle. When used with an external clock source, the module can be used as either a timer or counter and increments on every selected edge of the external source.

Timer1 is enabled by configuring the ON and GE bits in the TxCON and TxGCON registers, respectively. The table below displays the Timer1 enable selections.

Table 1. Timer1 Enable Selections
ON GE Timer1 Operation
1 1 Count Enabled
1 0 Always On
0 1 Off
0 0 Off