Datasheet
2013-2014 Microchip Technology Inc. DS70000689D-page 411
dsPIC33EPXXXGM3XX/6XX/7XX
30.0 SPECIAL FEATURES
dsPIC33EPXXXGM3XX/6XX/7XX devices include
several features intended to maximize application
flexibility and reliability, and minimize cost through
elimination of external components. These are:
• Flexible Configuration
• Watchdog Timer (WDT)
• Code Protection and CodeGuard™ Security
• JTAG Boundary Scan Interface
• In-Circuit Serial Programming™ (ICSP™)
• In-Circuit Emulation
30.1 Configuration Bits
In dsPIC33EPXXXGM3XX/6XX/7XX devices, the
Configuration bytes are implemented as volatile
memory. This means that configuration data must be
programmed each time the device is powered up.
Configuration data is stored at the top of the on-chip
program memory space, known as the Flash Configu-
ration bytes. Their specific locations are shown in
Table 30-1. The configuration data is automatically
loaded from the Flash Configuration bytes to the proper
Configuration Shadow registers during device Resets.
When creating applications for these devices, users
should always specifically allocate the location of the
Flash Configuration bytes for configuration data in their
code for the compiler. This is to make certain that pro-
gram code is not stored in this address when the code
is compiled.
The upper 2 bytes of all Flash Configuration
Words in program memory should always be
‘1111 1111 1111 1111’. This makes them appear
to be NOP instructions in the remote event that their
locations are ever executed by accident. Since Config-
uration bits are not implemented in the corresponding
locations, writing ‘1’s to these locations has no effect on
device operation.
The Configuration Flash bytes map is shown in
Table 30-1.
Note: This data sheet summarizes the features of
the dsPIC33EPXXXGM3XX/6XX/7XX family
of devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to the related section of the
“dsPIC33/PIC24 Family Reference Manual”,
which is available from the Microchip web
site (www.microchip.com).
Note: Configuration data is reloaded on all types
of device Resets.
Note: Performing a page erase operation on the
last page of program memory clears the
Flash Configuration bytes, enabling code
protection as a result. Therefore, users
should avoid performing page erase
operations on the last page of program
memory.