Datasheet

 2011-2012 Microchip Technology Inc. DS75018C-page 251
dsPIC33FJ06GS001/101A/102A/202A and dsPIC33FJ09GS302
22.0 SPECIAL FEATURES
The dsPIC33FJ06GS001/101A/102A/202A and
dsPIC33FJ09GS302 family of devices includes several
features that are included to maximize application
flexibility and reliability, and minimize cost through
elimination of external components. These features are:
• Flexible Configuration
• Watchdog Timer (WDT)
• Code Protection
• JTAG Boundary Scan Interface
• In-Circuit Serial Programming™ (ICSP™)
• In-Circuit Emulation
• Brown-out Reset (BOR)
22.1 Configuration Bits
The configuration bytes are implemented as volatile
memory. This means that configuration data must be
programmed each time the device is powered up. Con-
figuration data is stored in the words at the top of the
on-chip program memory space, known as the Flash
Configuration Words. Their specific locations are
shown in Table 22-1 and Table 22-2. The configuration
data is automatically loaded from the Flash Configura-
tion Words to the proper Configuration registers during
device Resets.
When creating applications for these devices, users
should always specifically allocate the location of the
Flash Configuration byte for configuration data. This is
to make certain that program 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 exe-
cuted by accident. Since Configuration bits are not
implemented in the corresponding locations, writing
‘1’s to these locations has no effect on device
operation.
The Configuration Flash Byte maps are shown in
Table 22-1 and Ta b l e 22-2.
The Constant Current Source Calibration register is
shown in Register 22-1.
Note 1: This data sheet summarizes the features
of the dsPIC33FJ06GS001/101A/102A/
202A and dsPIC33FJ09GS302 devices.
It is not intended to be a comprehensive
reference source. To complement the
information in this data sheet, refer to
Section 24. “Programming and Diag-
nostics” (DS70207) and Section 25.
“Device Configuration” (DS70194)
in the “dsPIC33F/PIC24H Family
Reference Manual”, which are avail-
able from the Microchip web site
(www.microchip.com).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.
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 Words, enabling code
protection as a result. Therefore, users
should avoid performing page erase
operations on the last page of program
memory