Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller SSOP 20 8-Bit 20 MHz I/O number 11

PIC12F635/PIC16F636/639

4.2.4.5 RA4/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

• a Timer1 gate input

• a crystal/resonator connection

• a clock output

FIGURE 4-5: BLOCK DIAGRAM OF RA4

4.2.4.6 RA5/T1CKI/OSC1/CLKIN

Figure 4-6 shows the diagram for this pin. The RA5 pin

is configurable to function as one of the following:

• a general purpose I/O

• a Timer1 clock input

• a crystal/resonator connection

• a clock input

FIGURE 4-6: BLOCK DIAGRAM OF RA5

I/O pi

VDD

VSS

XTAL

PORTA

TRISA

IOCA

FOSC/4

Oscillator

Circuit

OSC1

CLKOUT

Enable

RD PORTA

T1G To Timer1

INTOSC/

RC/EC

(2)

CLKOUT

Enable

Note 1: Oscillator modes are XT, HS, LP, LPTMR1 and

CLKOUT Enable.

2: With CLKOUT option.

Interrupt-on-

change

Data Bus

WPUDA

RAPU

WDA

VDD

Weak

VSS

CLK

(1)

Modes

I/O pin

VDD

VSS