PIC16F84A
TABLE 1-1
Pin Name
OSC1/CLKIN
OSC2/CLKOUT
PIC16F84A PINOUT DESCRIPTION
DIP
No.
16
15
SOIC
No.
16
15
SSOP
No.
18
19
I/O/P
Type
I
O
Buffer
Type
Description
ST/CMOS
(3)
Oscillator crystal input/external clock source input.
—
Oscillator crystal output. Connects to crystal or resonator in
crystal oscillator mode. In RC mode, OSC2 pin outputs
CLKOUT which has 1/4 the frequency of OSC1, and
denotes the instruction cycle rate.
Master clear (reset) input/programming voltage input. This
pin is an active low reset to the device.
PORTA is a bi-directional I/O port.
MCLR
4
4
4
I/P
ST
RA0
RA1
RA2
RA3
RA4/T0CKI
17
18
1
2
3
17
18
1
2
3
19
20
1
2
3
I/O
I/O
I/O
I/O
I/O
TTL
TTL
TTL
TTL
ST
Can also be selected to be the clock input to the TMR0
timer/counter. Output is open drain type.
PORTB is a bi-directional I/O port. PORTB can be software
programmed for internal weak pull-up on all inputs.
RB0/INT
RB1
RB2
RB3
RB4
RB5
RB6
RB7
V
SS
V
DD
Legend: I= input
6
7
8
9
10
11
12
13
5
14
6
7
8
9
10
11
12
13
5
14
7
8
9
10
11
12
13
14
5,6
15,16
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
P
P
TTL/ST
(
1)
TTL
TTL
TTL
TTL
TTL
TTL/ST
(2)
TTL/ST
(2)
—
—
RB0/INT can also be selected as an external interrupt
pin.
Interrupt on change pin.
Interrupt on change pin.
Interrupt on change pin. Serial programming clock.
Interrupt on change pin. Serial programming data.
Ground reference for logic and I/O pins.
Positive supply for logic and I/O pins.
O = output
I/O = Input/Output
P = power
— = Not used
TTL = TTL input
ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
2: This buffer is a Schmitt Trigger input when used in serial programming mode.
3: This buffer is a Schmitt Trigger input when configured in RC oscillator mode and a CMOS input otherwise.
DS35007A-page 4
Preliminary
©
1998 Microchip Technology Inc.
MICROCHIP [ MICROCHIP TECHNOLOGY ]
