PIC16F636-I Datasheet, PDF (54/234 Pages) Microchip Technology – 8/14-Pin, Flash-Based 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC12F635/PIC16F636/639
4.2.4
PIN DESCRIPTIONS AND
DIAGRAMS
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:
BLOCK DIAGRAM OF RA0
Analog
Input Mode⁽¹⁾
Data Bus
WR
WPUDA
RD
WPUDA
DQ
CK _Q
RAPU
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:
• 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
VDD
Weak
Weak
WR
WDA
RD
WDA
DQ
CK _Q
WR
PORTA
DQ
CK _Q
WR
TRISA
DQ
CK _Q
RD
TRISA
RD
PORTA
WR
IOCA
RD
IOCA
DQ
CK _Q
Interrupt-on-
Change
VDD
–
+
VT
01
Analog
Input Mode⁽¹⁾
IULP
VSS
ULPWUE
I/O pin
VSS
QD
EN
Q1
QD
EN
RD PORTA
Note 1: Comparator mode determines Analog Input mode.
DS41232D-page 52
© 2007 Microchip Technology Inc.