2007 Microchip Technology Inc.
DS39599G-page 7
PIC18F2220/2320/4220/4320
1.0
DEVICE OVERVIEW
This document contains device-specific information for
the following devices:
This family offers the advantages of all PIC18 micro-
controllers – namely, high computational performance
at an economical price with the addition of high-
endurance Enhanced Flash program memory. On top
of these features, the PIC18F2220/2320/4220/4320
family introduces design enhancements that make
these microcontrollers a logical choice for many
high-performance, power sensitive applications.
1.1
New Core Features
1.1.1
nanoWatt TECHNOLOGY
All of the devices in the PIC18F2220/2320/4220/4320
family incorporate a range of features that can signifi-
cantly reduce power consumption during operation.
Key items include:
Alternate Run Modes: By clocking the controller
from the Timer1 source or the internal oscillator
block, power consumption during code execution
can be reduced by as much as 90%.
Multiple Idle Modes: The controller can also run
with its CPU core disabled, but the peripherals are
still active. In these states, power consumption
can be reduced even further, to as little as 4%, of
normal operation requirements.
On-the-Fly Mode Switching: The power-managed
modes are invoked by user code during operation,
allowing the user to incorporate power-saving ideas
into their application’s software design.
Lower Consumption in Key Modules: The power
requirements for both Timer1 and the Watchdog
Timer have been reduced by up to 80%, with typical
values of 1.8 and 2.2
μA, respectively.
1.1.2
MULTIPLE OSCILLATOR OPTIONS
AND FEATURES
All of the devices in the PIC18F2220/2320/4220/4320
family offer nine different oscillator options, allowing
users a wide range of choices in developing application
hardware. These include:
Four Crystal modes using crystals or ceramic
resonators.
Two External Clock modes offering the option of
using two pins (oscillator input and a divide-by-4
clock output) or one pin (oscillator input with the
second pin reassigned as general I/O).
Two External RC Oscillator modes with the same
pin options as the External Clock modes.
An internal oscillator block, which provides a
31 kHz INTRC clock and an 8 MHz clock with
6 program selectable divider ratios (4 MHz to
125 kHz) for a total of 8 clock frequencies.
Besides its availability as a clock source, the internal
oscillator block provides a stable reference source that
gives the family additional features for robust
operation:
Fail-Safe Clock Monitor: This option constantly
monitors the main clock source against a refer-
ence signal provided by the internal oscillator. If a
clock failure occurs, the controller is switched to
the internal oscillator block, allowing for continued
low-speed operation or a safe application
shutdown.
Two-Speed Start-up: This option allows the
internal oscillator to serve as the clock source
from Power-on Reset, or wake-up from Sleep
mode, until the primary clock source is available.
This allows for code execution during what would
otherwise be the clock start-up interval and can
even allow an application to perform routine back-
ground activities and return to Sleep without
returning to full power operation.
1.2
Other Special Features
Memory Endurance: The Enhanced Flash cells
for both program memory and data EEPROM are
rated to last for many thousands of erase/write
cycles – up to 100,000 for program memory and
1,000,000 for EEPROM. Data retention without
refresh is conservatively estimated to be greater
than 40 years.
Self-Programmability: These devices can write
to their own program memory spaces under inter-
nal software control. By using a bootloader routine
located in the protected Boot Block at the top of
program memory, it becomes possible to create
an application that can update itself in the field.
Enhanced CCP Module: In PWM mode, this
module provides 1, 2 or 4 modulated outputs for
controlling half-bridge and full-bridge drivers.
Other features include Auto-Shutdown for dis-
abling PWM outputs on interrupt or other select
conditions and Auto-Restart to reactivate outputs
once the condition has cleared.
Addressable USART: This serial communication
module is capable of standard RS-232 operation
using the internal oscillator block, removing the
need for an external crystal (and its accompany-
ing power requirement) in applications that talk to
the outside world.
10-Bit A/D Converter: This module incorporates
programmable acquisition time, allowing for a
channel to be selected and a conversion to be ini-
tiated without waiting for a sampling period and
thus, reduce code overhead.
Extended Watchdog Timer (WDT): This
enhanced version incorporates a 16-bit prescaler,
allowing a time-out range from 4 ms to over
2 minutes, that is stable across operating voltage
and temperature.
PIC18F2220
PIC18F4220
PIC18F2320
PIC18F4320