PIC16F818/PIC16F819 pdf datash

PIC16F818/819 Data Sheet 18/20-Pin Enhanced Flash Microcontrollers with nanoWatt Technology

This document contains device specific information for
the operation of the PIC16F818/819 devices. Additional
information may be found in the PICmicro? Mid-Range
MCU Family Reference Manual (DS33023), which may
be downloaded from the Microchip web site. The
Reference Manual should be considered a complementary
document to this data sheet, and is highly
recommended reading for a better understanding of the
device architecture and operation of the peripheral
modules.
The PIC16F818/819 belongs to the Mid-Range family
of the PICmicro? devices. The devices differ from each
other in the amount of Flash program memory, data
memory and data EEPROM (see Table 1-1). A block
diagram of the devices is shown in Figure 1-1. These
devices contain features that are new to the PIC16
product line:
? Internal RC oscillator with eight selectable
frequencies, including 31.25 kHz, 125 kHz,
250 kHz, 500 kHz, 1 MHz, 2 MHz, 4 MHz and
8 MHz. The INTRC can be configured as the
system clock via the configuration bits. Refer to
Section 4.5 “Internal Oscillator Block” and
Section 12.1 “Configuration Bits” for further
details.
? The Timer1 module current consumption has
been greatly reduced from 20 μA (previous PIC16
devices) to 1.8 μA typical (32 kHz at 2V), which is
ideal for real-time clock applications. Refer to
Section 6.0 “Timer0 Module” for further details.
? The amount of oscillator selections has increased.
The RC and INTRC modes can be selected with
an I/O pin configured as an I/O or a clock output
(FOSC/4). An external clock can be configured
with an I/O pin. Refer to Section 4.0 “Oscillator
Configurations” for further details.