Datasheet
PIC18F2423/2523/4423/4523
DS39755C-page 10 © 2009 Microchip Technology Inc.
1.2 Other Special Features
• 12-Bit A/D Converter: This module incorporates
programmable acquisition time, allowing for a
channel to be selected and a conversion to be
initiated without waiting for a sampling period,
thereby reducing code overhead.
• 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 is possible to create an
application that can update itself in the field.
• Extended Instruction Set: The PIC18F2423/
2523/4423/4523 family introduces an optional
extension to the PIC18 instruction set that adds
eight new instructions and an Indexed Addressing
mode. This extension, enabled as a device con-
figuration option, has been specifically designed
to optimize re-entrant application code originally
developed in high-level languages, such as C.
• Enhanced CCP module: In PWM mode, this
module provides one, two or four modulated
outputs for controlling half-bridge and full-bridge
drivers. Other features include auto-shutdown, for
disabling PWM outputs on interrupt or other select
conditions, and auto-restart, to reactivate outputs
once the condition has cleared.
• Enhanced Addressable USART: This serial
communication module is capable of standard
RS-232 operation and provides support for the
LIN/J2602 bus protocol. Other enhancements
include automatic baud rate detection and a 16-bit
Baud Rate Generator for improved resolution.
When the microcontroller is using the internal
oscillator block, the EUSART provides stable
operation for applications that talk to the outside
world without using an external crystal (or its
accompanying power requirement).
• Extended Watchdog Timer (WDT): This
Enhanced version incorporates a 16-bit prescaler,
allowing an extended time-out range that is stable
across operating voltage and temperature. See
Section 4.0 “Electrical Characteristics” for
time-out periods.
1.3 Details on Individual Family
Members
Devices in the PIC18F2423/2523/4423/4523 family are
available in 28-pin and 40/44-pin packages. Block
diagrams for the two groups are shown in Figure 1-1
and Figure 1-2.
The devices are differentiated from each other in these
ways:
• Flash Program Memory:
- PIC18F2423/4423 devices – 16 Kbytes
- PIC18F2523/4523 devices – 32 Kbytes
• A/D Channels:
- PIC18F2423/2523 devices – 10
- PIC18F4423/4523 devices – 13
• I/O Ports:
- PIC18F2423/2523 devices – Three bidirectional
ports
- PIC18F4423/4523 devices – Five bidirectional
ports
• CCP and Enhanced CCP Implementation:
- PIC18F2423/2523 devices – Two standard
CCP modules
- PIC18F4423/4523 devices – One standard
CCP module and one ECCP module
• Parallel Slave Port – Present only on
PIC18F4423/4523 devices
All other features for devices in this family are identical.
These are summarized in Table 1-1.
The pinouts for all devices are listed in Table 1-2 and
Table 1-3.
Members of the PIC18F2423/2523/4423/4523 family
are available only as low-voltage devices, designated
by “LF” (such as PIC18LF2423), and function over an
extended V
DD range of 2.0V to 5.5V.