Microchip Technology DV164136 Data Sheet
PIC18F8722 FAMILY
DS39646C-page 8
© 2008 Microchip Technology Inc.
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:
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 reference
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.
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.
from Power-on Reset, or wake-up from Sleep
mode, until the primary clock source is available.
1.1.4
EXTERNAL MEMORY INTERFACE
In the unlikely event that 128 Kbytes of program
memory is inadequate for an application, the
PIC18F8527/8622/8627/8722 members of the family
also implement an external memory interface. This
allows the controller’s internal program counter to
address a memory space of up to 2 Mbytes,
permitting a level of data access that few 8-bit devices
can claim.
memory is inadequate for an application, the
PIC18F8527/8622/8627/8722 members of the family
also implement an external memory interface. This
allows the controller’s internal program counter to
address a memory space of up to 2 Mbytes,
permitting a level of data access that few 8-bit devices
can claim.
With the addition of new operating modes, the external
memory interface offers many new options, including:
memory interface offers many new options, including:
• Operating the microcontroller entirely from
external memory
• Using combinations of on-chip and external
memory, up to the 2-Mbyte limit
• Using external Flash memory for reprogrammable
application code or large data tables
• Using external RAM devices for storing large
amounts of variable data
1.1.5
EASY MIGRATION
Regardless of the memory size, all devices share the
same rich set of peripherals, allowing for a smooth
migration path as applications grow and evolve.
same rich set of peripherals, allowing for a smooth
migration path as applications grow and evolve.
The consistent pinout scheme used throughout the
entire family also aids in migrating to the next larger
device. This is true when moving between the 64-pin
members, between the 80-pin members, or even
jumping from 64-pin to 80-pin devices.
entire family also aids in migrating to the next larger
device. This is true when moving between the 64-pin
members, between the 80-pin members, or even
jumping from 64-pin to 80-pin devices.
1.2
Other Special Features
• Communications: The PIC18F8722 family
incorporates a range of serial communication
peripherals, including 2 independent Enhanced
USARTs and 2 Master SSP modules capable of
both SPI and I
peripherals, including 2 independent Enhanced
USARTs and 2 Master SSP modules capable of
both SPI and I
2
C (Master and Slave) modes of
operation. Also, one of the general purpose I/O
ports can be reconfigured as an 8-bit Parallel
Slave Port for direct processor-to-processor
communications.
ports can be reconfigured as an 8-bit Parallel
Slave Port for direct processor-to-processor
communications.
• CCP Modules: All devices in the family
incorporate two Capture/Compare/PWM (CCP)
modules and three Enhanced CCP (ECCP)
modules to maximize flexibility in control
applications. Up to four different time bases may
be used to perform several different operations at
once. Each of the three ECCP modules offer up to
four PWM outputs, allowing for a total of
12 PWMs. The ECCPs also offer many beneficial
features, including polarity selection,
Programmable Dead-Time, Auto-Shutdown and
Restart and Half-Bridge and Full-Bridge
Output modes.
modules and three Enhanced CCP (ECCP)
modules to maximize flexibility in control
applications. Up to four different time bases may
be used to perform several different operations at
once. Each of the three ECCP modules offer up to
four PWM outputs, allowing for a total of
12 PWMs. The ECCPs also offer many beneficial
features, including polarity selection,
Programmable Dead-Time, Auto-Shutdown and
Restart and Half-Bridge and Full-Bridge
Output modes.
• Self-Programmability: These devices can write
to their own program memory spaces under
internal 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.
internal 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.
• Extended Instruction Set: The PIC18F8722
family introduces an optional extension to the
PIC18 instruction set, which adds 8 new instruc-
tions and an Indexed Addressing mode. This
extension, enabled as a device configuration
option, has been specifically designed to optimize
re-entrant application code originally developed in
high-level languages, such as C.
PIC18 instruction set, which adds 8 new instruc-
tions and an Indexed Addressing mode. This
extension, enabled as a device configuration
option, has been specifically designed to optimize
re-entrant application code originally developed in
high-level languages, such as C.
• 10-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 and
thus, reduce code overhead.
channel to be selected and a conversion to be
initiated without waiting for a sampling period and
thus, reduce code overhead.
• 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 28.0 “Electrical Characteristics” for
time-out periods.
allowing an extended time-out range that is stable
across operating voltage and temperature. See
Section 28.0 “Electrical Characteristics” for
time-out periods.