PIC16F676 Microchip Technology Inc., PIC16F676 Datasheet - Page 26

• Manufacturer Part Number: PIC16F676
• Description: 14-pin, Flash-based 8-bit Cmos Microcontroller
• Manufacturer: Microchip Technology Inc.

PIC16F630/676
3.2.3.5
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:
DS40039E-page 24
PORTA
PORTA
WPUA
WPUA
Data Bus
TRISA
TRISA
Interrupt-on-Change
IOCA
IOCA
Note 1: CLK modes are XT, HS, LP, LPTMR1 and CLKOUT
WR
WR
WR
WR
RD
RD
RD
RD
2: With CLKOUT option.
Enable.
D
D
D
D
To TMR1 T1G
To A/D Converter
CK
CK
CK
CK
RA4/AN3/T1G/OSC2/CLKOUT
Q
Q
Q
Q
Q
Q
Q
Q
Input Mode
BLOCK DIAGRAM OF RA4
Analog
F
OSC1
OSC
INTOSC/
RC/EC
CLKOUT
CLKOUT
Enable
Enable
Input Mode
/4
RAPU
RD PORTA
CLKOUT
Enable
Analog
Oscillator
(2)
Modes
Q
Q
1
0
CLK
Circuit
EN
EN
(1)
D
D
V
DD
Weak
V
V
DD
SS
I/O pin
3.2.3.6
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:
PORTA
PORTA
WPUA
WPUA
Data Bus
TRISA
TRISA
IOCA
IOCA
Interrupt-on-Change
WR
WR
WR
WR
RD
RD
RD
RD
Note
D
D
D
D
To TMR1 or CLKGEN
CK
CK
CK
CK
1: Timer1 LP Oscillator enabled.
2: When using Timer1 with LP oscillator, the Schmitt
RA5/T1CKI/OSC1/CLKIN
Trigger is by-passed.
Q
Q
Q
Q
Q
Q
Q
Q
BLOCK DIAGRAM OF RA5
INTOSC
© 2007 Microchip Technology Inc.
Mode
OSC2
INTOSC
RAPU
RD PORTA
Mode
Oscillator
TMR1LPEN
Q
Q
Circuit
EN
EN
D
D
V
(1)
DD
Weak
V
V
DD
SS
I/O pin
(1)