16.13 MCLR/VPP/RA3 Pin

The MCLR/VPP pin is an input-only pin. Its operation is controlled by the MCLRE Configuration bit. When selected as a PORT pin (MCLRE = 0), it functions as a digital input-only pin; as such, it does not have TRISx and LATx bits associated with its operation. Otherwise, it functions as the device’s Master Clear input. In either configuration, the MCLR/VPP pin also functions as the programming voltage input pin during high-voltage programming.

The MCLR/VPP pin is a read-only bit and will read ‘1’ when MCLRE = 1 (i.e., Master Clear enabled).

Important: On a Power-on Reset (POR), the MCLR/VPP pin is enabled as a digital input-only if Master Clear functionality is disabled.

The MCLR/VPP pin has an individually controlled internal weak pull-up. When set, the corresponding WPU bit enables the pull-up. When the MCLR/VPP pin is configured as MCLR (MCLRE = 1 and LVP = 0) or configured for Low-Voltage Programming (MCLRE = x and LVP = 1), the pull-up is always enabled, and the WPU bit has no effect.