# Level-Triggered Hardware Limit One-Shot Modes

The Level-Triggered Hardware Limit One-Shot modes hold the timer in Reset on an external Reset level and start counting when both the ON bit is set and the external signal is not at the Reset level. If one of either the external signal is not in Reset or the ON bit is set, then the other signal being set/made active will start the timer. Reset levels are selected as follows:

• Low Reset level (MODE<4:0> = 10110)
• High Reset level (MODE<4:0> = 10111)

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, the timer will stay in Reset until both the ON bit is set and the external signal is not at the Reset level.

When Level-Triggered Hardware Limit One-Shot modes are used in conjunction with the CCP PWM operation, the PWM drive goes active with either the external signal edge or the setting of the ON bit, whichever of the two starts the timer.

Figure 1. Level-Triggered hardware Limit one-Shot Mode Timing Diagram (MODE = 10110)
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.