PIC16F631/677/685/687/689/690
4.2.5
PIN DESCRIPTIONS AND
DIAGRAMS
4.2.5.1
RA0/AN0/C1IN+/ICSPDAT/ULPWU
Figure 4-2 shows the diagram for this pin. The
RA0/AN0/C1IN+/ICSPDAT/ULPWU 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 or the A/D Converter (ADC),
refer to the appropriate section in this data sheet.
• a general purpose I/O
• an analog input for the ADC (except PIC16F631)
• an analog input to Comparator C1
• In-Circuit Serial Programming™ data
• an analog input for the Ultra Low-Power Wake-up
FIGURE 4-1:
BLOCK DIAGRAM OF RA0
Analog(1)
Input Mode
VDD
Data Bus
D
Q
Q
Weak
CK
WR
WPUDA
RABPU
RD
VDD
WPUDA
D
Q
Q
I/O Pin
WR
CK
PORTA
VSS
-
+
VT
D
Q
Q
WR
TRISA
CK
IULP
0
1
RD
TRISA
Analog(1)
Input Mode
VSS
ULPWUE
RD
PORTA
D
Q
Q
Q
D
D
CK
WR
IOCA
Q3
EN
RD
IOCA
Q
EN
Interrupt-on-Change
RD PORTA
To Comparator
To A/D Converter(2)
Note 1: ANSEL determines Analog Input mode.
2: Not implemented on PIC16F631.
DS41262D-page 64
© 2007 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
