4.2.2 Master Clear (MCLR) Pin

The MCLR pin provides two specific device functions:

  • Device Reset
  • Device programming and debugging

Pulling the MCLR pin low, generates a device Reset. Module Basic Connection and Interface Diagram illustrates a typical MCLR circuit (see Module Basic Connection and Interface Diagrams in the Basic Connection Requirement from Related Links).

The WBZ35x module has sufficient filtering (0.1 μF) and pull-up (10k) on the Reset line. On a typical application, there is no need for extra filtering on this pin.

Figure 4-6. Example of MCLR Pin Connections
Note:
  1. 470Ω ≤ R1 ≤ 1 kΩ limits any current flowing into MCLR from the external capacitor C, in the event of MCLR pin breakdown, due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). Ensure that the MCLR pin VIH and VIL specifications are met without interfering with the Debug/Programmer tools.
  2. The capacitor can be sized to prevent unintentional Resets from brief glitches or to extend the device Reset period during POR.