Datasheet
PIC16F630/676
DS40039E-page 24 © 2007 Microchip Technology Inc.
3.2.3.5 RA4/AN3/T1G/OSC2/CLKOUT
Figure 3-4 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 A/D (PIC16F676 only)
• a TMR1 gate input
• a crystal/resonator connection
• a clock output
FIGURE 3-4: BLOCK DIAGRAM OF RA4
3.2.3.6 RA5/T1CKI/OSC1/CLKIN
Figure 3-5 shows the diagram for this pin. The RA5 pin
is configurable to function as one of the following:
• a general purpose I/O
•a TMR1 clock input
• a crystal/resonator connection
• a clock input
FIGURE 3-5: BLOCK DIAGRAM OF RA5
I/O pin
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
Analog
Input Mode
Data Bus
WR
WPUA
RD
WPUA
RD
PORTA
WR
PORTA
WR
TRISA
RD
TRISA
WR
IOCA
RD
IOCA
Interrupt-on-Change
F
OSC/4
To A/D Converter
Oscillator
Circuit
OSC1
CLKOUT
0
1
CLKOUT
Enable
Enable
Analog
Input Mode
RAPU
RD PORTA
To TMR1 T1G
INTOSC/
RC/EC
(2)
CLK
(1)
Modes
CLKOUT
Enable
Note 1: CLK modes are XT, HS, LP, LPTMR1 and CLKOUT
Enable.
2: With CLKOUT option.
I/O pin
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
Data Bus
WR
WPUA
RD
WPUA
RD
PORTA
WR
PORTA
WR
TRISA
RD
TRISA
WR
IOCA
RD
IOCA
Interrupt-on-Change
To TMR1 or CLKGEN
INTOSC
Mode
RD PORTA
INTOSC
Mode
RAPU
Oscillator
Circuit
OSC2
(1)
Note 1: Timer1 LP Oscillator enabled.
2: When using Timer1 with LP oscillator, the Schmitt
Trigger is by-passed.
TMR1LPEN
(1)