PIC16F84A_07 Datasheet, PDF (5/88 Pages) Microchip Technology – 18-pin Enhanced FLASH/EEPROM 8-bit Microcontroller

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
downloaded from the Microchip website. The Refer-
ence Manual should be considered a complementary
document to this data sheet, and is highly recom-
mended reading for a better understanding of the
device architecture 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
Table 1-1 details the pinout of the device with descrip-
tions and details for each pin.
FIGURE 1-1:
PIC16F84A BLOCK DIAGRAM
FLASH
Program
Memory
1K x 14
13
Program Counter
8 Level Stack
(13-bit)
Program
Bus ¹⁴
Instruction Register
5
Direct Addr
Data Bus ₈
RAM
File Registers
68 x 8
7 _{RAM Addr}
Addr Mux
7 Indirect
Addr
FSR reg
STATUS reg
8
EEPROM Data Memory
EEDATA
EEPROM
Data Memory
64 x 8
TMR0
EEADR
RA4/T0CKI
Instruction
Decode &
Control
Timing
Generation
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
MUX
ALU
W reg
8
I/O Ports
RA3:RA0
RB7:RB1
RB0/INT
OSC2/CLKOUT
OSC1/CLKIN
MCLR VDD, VSS
© 2001 Microchip Technology Inc.
DS35007B-page 3