10.9 Start-Up Sequence

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

  1. Power-up Timer runs to completion (if enabled).
  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 10-3). This is useful for testing purposes or for synchronizing more than one device operating in parallel.

Figure 10-3. Reset Start-Up Sequence
Note:
  1. Code execution begins 10 FOSC cycles after the FOSC clock is released.