MA180023 Microchip Technology, MA180023 Datasheet - Page 389

• Manufacturer Part Number: MA180023
• Description: MODULE PLUG-IN PIC18F46J11 PIM
• Manufacturer: Microchip Technology
• Series: PIC®r

Specifications of MA180023

• Accessory Type: Plug-In Module (PIM) - PIC18F46J11
• Tool / Board Applications: General Purpose MCU, MPU, DSP, DSC
• Mcu Supported Families: PIC18
• Supported Devices: Stand-alone Or W/ HPC(DM183022) Or PIC18(DM183032)
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18FxxJxx
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: HPC Explorer Board (DM183022) or PIC18 Explorer Board (DM183032)
• For Use With: DM183032 - BOARD EXPLORER PICDEM PIC18DM183022 - BOARD DEMO PIC18FXX22 64/80TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

25.0
PIC18F46J11 family devices include several features
intended to maximize reliability and minimize cost
through elimination of external components. These are:
• Oscillator Selection
• Resets:
• Interrupts
• Watchdog Timer (WDT)
• Fail-Safe Clock Monitor (FSCM)
• Two-Speed Start-up
• Code Protection
• In-Circuit Serial Programming (ICSP)
The oscillator can be configured for the application
depending on frequency, power, accuracy and cost. All
of the options are discussed in detail in Section 2.0
“Oscillator Configurations”.
A complete discussion of device Resets and interrupts
is available in previous sections of this data sheet. In
addition to their Power-up and Oscillator Start-up
Timers provided for Resets, the PIC18F46J11 family of
devices have a configurable Watchdog Timer (WDT),
which is controlled in software.
The inclusion of an internal RC oscillator also provides
the additional benefits of a Fail-Safe Clock Monitor
(FSCM) and Two-Speed Start-up. FSCM provides for
background monitoring of the peripheral clock and
automatic switchover in the event of its failure.
Two-Speed Start-up enables code to be executed
almost immediately on start-up, while the primary clock
source completes its start-up delays.
All of these features are enabled and configured by
setting the appropriate Configuration register bits.
25.1
The Configuration bits can be programmed to select
various device configurations. The configuration data is
stored in the last four words of Flash program memory;
Figure 5-1 depicts this. The configuration data gets
loaded into the volatile Configuration registers,
CONFIG1L through CONFIG4H, which are readable
and mapped to program memory starting at location
300000h.
Table 25-2 provides a complete list. A detailed explana-
tion of the various bit functions is provided in
Register 25-1 through Register 25-6.
© 2009 Microchip Technology Inc.
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
SPECIAL FEATURES OF THE
CPU
Configuration Bits
PIC18F46J11 FAMILY
25.1.1
Unlike some previous PIC18 microcontrollers, devices
of the PIC18F46J11 family do not use persistent mem-
ory registers to store configuration information. The
Configuration
CONFIG4H, are implemented as volatile memory.
Immediately after power-up, or after a device Reset,
the microcontroller hardware automatically loads the
CONFIG1L through CONFIG4L registers with configu-
ration data stored in nonvolatile Flash program
memory. The last four words of Flash program memory,
known as the Flash Configuration Words (FCW), are
used to store the configuration data.
Table 25-1 provides the Flash program memory, which
will be loaded into the corresponding Configuration
register.
When creating applications for these devices, users
should always specifically allocate the location of the
FCW for configuration data. This is to make certain that
program code is not stored in this address when the
code is compiled.
The four Most Significant bits (MSb) of the FCW corre-
sponding to CONFIG1H, CONFIG2H, CONFIG3H and
CONFIG4H should always be programmed to ‘1111’.
This makes these FCWs appear to be NOP instructions
in the remote event that their locations are ever
executed by accident.
To prevent inadvertent configuration changes during
code
CONFIG1L through CONFIG4L, are loaded only once
per power-up or Reset cycle. User’s firmware can still
change the configuration by using self-reprogramming
to modify the contents of the FCW.
Modifying the FCW will not change the active contents
being used in the CONFIG1L through CONFIG4H
registers until after the device is reset.
execution,
CONSIDERATIONS FOR
CONFIGURING THE PIC18F46J11
FAMILY DEVICES
registers,
the
Configuration
CONFIG1L
DS39932C-page 389
registers,
through