Datasheet

PIC12F635/PIC16F636/639
DS41232D-page 54 © 2007 Microchip Technology Inc.
4.2.4.4 RA3/MCLR/VPP
Figure 4-4 shows the diagram for this pin. The RA3 pin
is configurable to function as one of the following:
• a general purpose input
• as Master Clear Reset with weak pull-up
• a high-voltage detect for Program mode entry
FIGURE 4-4: BLOCK DIAGRAM OF RA3
Input
V
SS
D
Q
CK
Q
D
EN
Q
Data Bus
RD PORTA
RD
PORTA
WR
IOCA
RD
IOCA
Reset
MCLRE
RD
TRISA
VSS
D
EN
Q
MCLRE
VDD
Weak
MCLRE
Interrupt-on-
change
pin
HV Detect
Program
Mode
Q1
WURE
Sleep