PIC12F635/PIC16F636/639
4.2.4
PIN DESCRIPTIONS AND
DIAGRAMS
4.2.4.1
RA0/C1IN+/ICSPDAT/ULPWU
Figure 4-2 shows the diagram for this pin. The RA0 pin
is configurable to function as one of the following:
Each PORTA pin is multiplexed with other functions. The
pins and their combined functions are briefly described
here. For specific information about individual functions,
such as the comparator, refer to the appropriate section
in this data sheet.
• a general purpose I/O
• an analog input to the comparator
• In-Circuit Serial Programming™ data
• an analog input for the Ultra Low-Power Wake-up
FIGURE 4-1:
BLOCK DIAGRAM OF RA0
Analog
Input Mode(1)
VDD
Data Bus
D
Q
Q
Weak
CK
WR
WPUDA
RAPU
RD
Weak
WPUDA
D
Q
Q
CK
WR
WDA
VDD
RD
WDA
D
Q
Q
I/O pin
WR
CK
PORTA
–
+
VSS
VT
D
Q
Q
WR
TRISA
CK
IULP
0
1
RD
TRISA
Analog
Input Mode(1)
VSS
ULPWUE
RD
PORTA
D
Q
Q
Q
D
D
CK
WR
IOCA
Q1
EN
RD
IOCA
Interrupt-on-
Change
Q
EN
RD PORTA
Note 1: Comparator mode determines Analog Input mode.
DS41232D-page 52
© 2007 Microchip Technology Inc.
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