PIC16F688 Datasheet, PDF (38/174 Pages) Microchip Technology – 14-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F688
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 individ-
ual functions such as the comparator or the A/D, refer
to the appropriate section in this data sheet.
4.2.4.1 RA0/AN0/C1IN+/ICSPDAT/ULPWU
Figure • 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 A/D
• an analog input to the comparator
• an analog input to the Ultra Low-Power Wake-up
• In-Circuit Serial Programming™ data
4.2.4.2 RA1/AN1/C1IN-/VREF/ICSPCLK
Figure • 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 A/D
• an analog input to the comparator
• a voltage reference input for the A/D
• In-Circuit Serial Programming clock
FIGURE 4-2:
Data Bus
DQ
WR
WPUA
CK _Q
RD
WPUA
BLOCK DIAGRAM OF RA1
Analog⁽¹⁾
Input Mode
VDD
Weak
RAPU
DQ
WR
PORTA
CK _Q
WR
TRISA
DQ
CK _Q
RD
TRISA
VDD
I/O pin
VSS
Analog⁽¹⁾
Input Mode
RD
PORTA
DQ
WR
IOCA
CK _Q
RD
IOCA
QD
EN
Q3
QD
EN
Interrupt-on-
change
RD PORTA
To Comparator
To A/D Converter
Note 1: Comparator mode and ANSEL determines analog
input mode.
DS41203B-page 36
Preliminary
 2004 Microchip Technology Inc.