PIC16F630/676
3.2.3
PIN DESCRIPTIONS AND
DIAGRAMS
FIGURE 3-1:
BLOCK DIAGRAM OF RA0
AND RA1 PINS
Analog
Input Mode
Each PORTA pin is multiplexed with other functions.
The pins and their combined functions are briefly
described here. For specific information about individ-
ual functions such as the comparator or the A/D, refer
to the appropriate section in this Data Sheet.
Data Bus
D
Q
Q
VDD
WR
CK
Weak
WPUA
RAPU
RD
WPUA
3.2.3.1
RA0/AN0/CIN+
Figure 3-1 shows the diagram for this pin. The RA0 pin
is configurable to function as one of the following:
VDD
D
Q
Q
• a general purpose I/O
WR
PORTA
CK
• an analog input for the A/D (PIC16F676 only)
• an analog input to the comparator
I/O pin
D
Q
Q
3.2.3.2
RA1/AN1/CIN-/VREF
WR
TRISA
Figure 3-1 shows the diagram for this pin. The RA1 pin
is configurable to function as one of the following:
CK
VSS
Analog
• as a general purpose I/O
Input Mode
RD
TRISA
• an analog input for the A/D (PIC16F676 only)
• an analog input to the comparator
RD
PORTA
• a voltage reference input for the A/D (PIC16F676
only)
D
Q
Q
Q
Q
D
CK
WR
IOCA
EN
RD
IOCA
D
EN
Interrupt-on-Change
RD PORTA
To Comparator
To A/D Converter
DS40039E-page 22
© 2007 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
