Datasheet

© 2007 Microchip Technology Inc. DS41202F-page 35
PIC16F684
4.2.5 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 or the
ADC, refer to the appropriate section in this data sheet.
4.2.5.1 RA0/AN0/C1IN+/ICSPDAT/ULPWU
Figure 4-1 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 for the ADC
an analog non-inverting input to the comparator
In-Circuit Serial Programming data
an analog input for the Ultra Low-Power Wake-Up
4.2.5.2 RA1/AN1/C1IN-/VREF/ICSPCLK
Figure 4-2 shows the diagram for this pin. The RA1 pin
is configurable to function as one of the following:
a general purpose I/O
an analog input for the ADC
an analog inverting input to the comparator
a voltage reference input for the ADC
In-Circuit Serial Programming clock
FIGURE 4-1: BLOCK DIAGRAM OF RA0
VDD
VSS
D
Q
CK
Q
D
Q
CK
Q
D
Q
CK
Q
D
Q
CK
Q
VDD
D
EN
Q
D
EN
Q
Weak
RD PORTA
RD
WR
WR
RD
WR
IOCA
RD
IOCA
Interrupt-on-
To Comparator
Analog
(1)
Input Mode
RAPU
Analog
(1)
Input Mode
Change
Q3
WR
RD
01
IULP
WPUA
Data Bus
WPUA
PORTA
TRISA
TRISA
PORTA
Note 1: Comparator mode and ANSEL determines Analog Input mode.
-
+
V
T
ULPWUE
To A/D Converter
VSS
I/O Pin