# Level Reset, Edge-Triggered Hardware Limit One-Shot Modes

In Level -Triggered One-Shot mode the timer count is reset on the external signal level and starts counting on the rising/falling edge of the transition from Reset level to the active level while the ON bit is set. Reset levels are selected as follows:

• Low Reset level (MODE<4:0> = 01110)
• High Reset level (MODE<4:0> = 01111)

When the timer count matches the PRx period count, the timer is reset and the ON bit is cleared. When the ON bit is cleared by either a PRx match or by software control, a new external signal edge is required after the ON bit is set to start the counter.

When Level-Triggered Reset One-Shot mode is used in conjunction with the CCP PWM operation, the PWM drive goes active with the external signal edge that starts the timer. The PWM drive goes inactive when the timer count equals the CCPRx pulse width count. The PWM drive does not go active when the timer count clears at the PRx period count match.

Figure 1. Low Level Reset, Edge-Triggered hardware Limit one-Shot Mode Timing Diagram (MODE = 01110)
Note:
1. 1.BSF and BCF represent Bit-Set File and Bit-Clear File instructions executed by the CPU to set or clear the ON bit of TxCON. CPU execution is asynchronous to the timer clock input.