PIC16F84A
1.0
DEVICE OVERVIEW
This document contains device-specific information for
the operation of the PIC16F84A device. Additional
information may be found in the PICmicro™ Mid-Range
Reference Manual, (DS33023), which may be down-
loaded from the Microchip website. The Reference
Manual should be considered a complementary docu-
ment to this data sheet, and is highly recommended
reading for a better understanding of the device archi-
tecture and operation of the peripheral modules.
The PIC16F84A belongs to the mid-range family of the
PICmicro™ microcontroller devices. A block diagram of
the device is shown in Figure 1-1.
The program memory contains 1K words, which trans-
lates to 1024 instructions, since each 14-bit program
memory word is the same width as each device instruc-
tion. The data memory (RAM) contains 68 bytes. Data
EEPROM is 64 bytes.
There are also 13 I/O pins that are user-configured on
a pin-to-pin basis. Some pins are multiplexed with other
device functions. These functions include:
• External interrupt
• Change on PORTB interrupt
• Timer0 clock input
tions and details for each pin.
FIGURE 1-1:
PIC16F84A BLOCK DIAGRAM
13
Data Bus
Program Counter
8
EEPROM Data Memory
Flash
Program
Memory
PIC16F84A
1K x 14
Program
Bus
8 Level Stack
(13-bit)
RAM
File Registers
PIC16F84A
68 x 8
7
RAM Addr
EEDATA
EEPROM
Data Memory
64 x 8
14
EEADR
Instruction reg
5
Direct Addr
Addr Mux
7
Indirect
Addr
TMR0
FSR reg
RA4/T0CKI
STATUS reg
8
Power-up
Timer
Instruction
Decode &
Control
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
W reg
ALU
MUX
8
I/O Ports
RA3:RA0
RB7:RB1
Timing
Generation
RB0/INT
OSC2/CLKOUT
OSC1/CLKIN
MCLR
V
DD
, V
SS
©
1998 Microchip Technology Inc.
Preliminary
DS35007A-page 3
MICROCHIP [ MICROCHIP TECHNOLOGY ]
