Start-Up Sequence

Upon the release of a POR or BOR, the following must occur before the device will begin executing:

  1. 1.Power-up Timer runs to completion (if enabled).
  2. 2.MCLR must be released (if enabled).

The Power-up Timer runs independently of MCLR Reset. If MCLR is kept low long enough, the Power-up Timer will expire. Upon bringing MCLR high, the device will begin execution after 10 FOSC cycles (see Figure 1). This is useful for testing purposes or for synchronizing more than one device operating in parallel.

Figure 1. Reset Start-Up Sequence
  1. 1.Code execution begins 10 FOSC cycles after the FOSC clock is released.