PIC16F684_07 Datasheet, PDF (39/192 Pages) Microchip Technology – 14-Pin, Flash-Based 8-Bit CMOS Microcontrollers with nanoWatt Technology

4.2.5.4 RA3/MCLR/VPP
Figure 4-4 shows the diagram for this pin. The RA3 pin
is configurable to function as one of the following:
• a general purpose input
• as Master Clear Reset with weak pull-up
FIGURE 4-4:
BLOCK DIAGRAM OF RA3
MCLRE
VDD
Weak
Data Bus
Reset
RD
VSS
TRISA
RD
PORTA
DQ
WR
IOCA
CK _Q
RD
IOCA
Interrupt-on-
Change
MCLRE
MCLRE
QD
EN
QD
EN
RD PORTA
Input
Pin
VSS
Q3
PIC16F684
4.2.5.5 RA4/AN3/T1G/OSC2/CLKOUT
Figure 4-5 shows the diagram for this pin. The RA4 pin
is configurable to function as one of the following:
• a general purpose I/O
• an analog input for the ADC
• a Timer1 gate (count enable)
• a crystal/resonator connection
• a clock output
FIGURE 4-5:
BLOCK DIAGRAM OF RA4
Data Bus
DQ
WR
WPUA
CK _Q
Analog⁽³⁾
Input Mode _CLK(1)
Modes
VDD
Weak
RD
WPUA
DQ
WR
PORTA
CK _Q
WR
TRISA
DQ
CK _Q
RD
TRISA
RD
PORTA
DQ
WR
IOCA
CK _Q
RD
IOCA
RAPU
Oscillator
Circuit
OSC1
CLKOUT
Enable
FOSC/4 1
0
CLKOUT
Enable
INTOSC/
RC/EC⁽²⁾
CLKOUT
Enable
Analog
Input Mode
VDD
I/O Pin
VSS
QD
EN
Q3
QD
Interrupt-on-
Change
To T1G
To A/D Converter
EN
RD PORTA
Note 1: CLK modes are XT, HS, LP, LPTMR1 and CLKOUT
Enable.
2: With CLKOUT option.
3: Analog Input mode comes from ANSEL.
© 2007 Microchip Technology Inc.
DS41202F-page 37