Datasheet

2010 Microchip Technology Inc. DS39951C-page 59
PIC24FJ64GA104 FAMILY
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
•MCLR
: Pin Reset
•SWR: RESET Instruction
WDT: Watchdog Timer Reset
BOR: Brown-out Reset
CM: Configuration Mismatch Reset
TRAPR: Trap Conflict Reset
IOPUWR: Illegal Opcode Reset
UWR: Uninitialized W Register Reset
A simplified block diagram of the Reset module is
shown in Figure 6-1.
Any active source of Reset will make the SYSRST
signal active. Many registers associated with the CPU
and peripherals are forced to a known Reset state.
Most registers are unaffected by a Reset; their status is
unknown on POR and unchanged by all other Resets.
All types of device Reset will set a corresponding status
bit in the RCON register to indicate the type of Reset
(see Register 6-1). A Power-on Reset will clear all bits,
except for the BOR and POR bits (RCON<1:0>), which
are set. The user may 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 will 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 data sheet.
FIGURE 6-1: RESET SYSTEM BLOCK DIAGRAM
Note: This data sheet summarizes the features
of this group of PIC24F devices. It is not
intended to be a comprehensive reference
source. For more information, refer to the
“PIC24F Family Reference Manual”,
Section 7. “Reset” (DS39712).
Note: Refer to the specific peripheral or CPU
section 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 will be meaningful.
MCLR
VDD
VDD Rise
Detect
POR
Sleep or Idle
Brown-out
Reset
Enable Voltage Regulator
RESET
Instruction
WDT
Module
Glitch Filter
BOR
Trap Conflict
Illegal Opcode
Uninitialized W Register
SYSRST
Configuration Mismatch