PIC16F639 Microchip Technology Inc., PIC16F639 Datasheet - Page 54

• Manufacturer Part Number: PIC16F639
• Description: 8/14-pin Flash-based, 8-bit Cmos Microcontrollers With Nanowatt Technology
• Manufacturer: Microchip Technology Inc.

PIC12F635/PIC16F636/639
4.2.4
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.
FIGURE 4-1:
DS41232D-page 52
Note 1:
PIN DESCRIPTIONS AND
DIAGRAMS
Data Bus
WPUDA
WPUDA
PORTA
PORTA
TRISA
TRISA
IOCA
IOCA
WDA
WDA
Interrupt-on-
WR
WR
WR
WR
WR
RD
RD
RD
RD
RD
Change
Comparator mode determines Analog Input mode.
BLOCK DIAGRAM OF RA0
D
D
D
D
D
CK
CK
CK
CK
CK
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Input Mode
Analog
RAPU
(1)
RD PORTA
Input Mode
Analog
Q
Q
4.2.4.1
Figure 4-2 shows the diagram for this pin. The RA0 pin
is configurable to function as one of the following:
• 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
(1)
EN
EN
D
D
0
1
V
Q1
Weak
Weak
DD
RA0/C1IN+/ICSPDAT/ULPWU
–
+
ULPWUE
V
SS
I
ULP
© 2007 Microchip Technology Inc.
V
T
V
V
DD
SS
I/O pin