Datasheet

© 2007-2012 Microchip Technology Inc. DS70292G-page 77
dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/X04, AND dsPIC33FJ128GPX02/X04
6.0 RESETS
The Reset module combines all reset sources and
controls the device Master Reset Signal, SYSRST
. The
following is a list of device Reset sources:
• POR: Power-on Reset
• BOR: Brown-out Reset
•MCLR
: Master Clear Pin Reset
•SWR: RESET Instruction
• WDTO: Watchdog Timer Reset
• CM: Configuration Mismatch Reset
• TRAPR: Trap Conflict Reset
• IOPUWR: Illegal Condition Device Reset
- Illegal Opcode Reset
- Uninitialized W Register Reset
- Security Reset
A simplified block diagram of the Reset module is
shown in Figure 6-1.
Any active source of reset will make the SYSRST
sig-
nal active. On system Reset, some of the registers
associated with the CPU and peripherals are forced to
a known Reset state and some are unaffected.
All types of device Reset sets a corresponding status
bit in the RCON register to indicate the type of Reset
(see Register 6-1).
A POR clears all the bits, except for the POR bit
(RCON<0>), that are set. The user application can set
or clear any bit at any time during code execution. The
RCON bits only serve as status bits. Setting a particular
Reset status bit in software does not cause a device
Reset to occur.
The RCON register also has other bits associated with
the Watchdog Timer and device power-saving states.
The function of these bits is discussed in other sections
of this manual.
FIGURE 6-1: RESET SYSTEM BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the dsPIC33FJ32GP302/304,
dsPIC33FJ64GPX02/X04, and
dsPIC33FJ128GPX02/X04 families of
devices. It is not intended to be a compre-
hensive reference source. To comple-
ment the information in this data sheet,
refer to Section 8. “Reset” (DS70192) of
the “dsPIC33F/PIC24H Family Reference
Manual”, which is available from the
Microchip website (www.microchip.com).
2: Some registers and associated bits
described in this section may not be avail-
able on all devices. Refer to Section 4.0
“Memory Organization” in this data
sheet for device-specific register and bit
information.
Note: Refer to the specific peripheral section or
Section 3.0 “CPU” of this manual for
register Reset states.
Note: The status bits in the RCON register
should be cleared after they are read so
that the next RCON register value after a
device Reset is meaningful.
MCLR
VDD
Internal
Regulator
BOR
Sleep or Idle
RESET Instruction
WDT
Module
Glitch Filter
Trap Conflict
Illegal Opcode
Uninitialized W Register
SYSRST
VDD Rise
Detect
POR
Configuration Mismatch