Datasheet

© 2011-2012 Microchip Technology Inc. Preliminary DS39997C-page 63
PIC24FJ16MC101/102 AND PIC24FJ32MC101/102/104
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 set a corresponding status bit
in the RCON register to indicate the type of Reset (see
Register 6-1).
All bits that are set, with the exception of the POR bit
(RCON<0>), are cleared during a POR event. 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 data sheet.
FIGURE 6-1: RESET SYSTEM BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the PIC24FJ16MC101/102 and
PIC24FJ32MC101/102/104 family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 7. “Reset”
(DS39712) in the “PIC24F Family
Reference Manual”, which is available
from the Microchip web site
(www.microchip.com).
2: It is important to note that the
specifications in Section 26.0 “Electri-
cal Characteristics” of this data sheet,
supercede any specifications that may be
provided in PIC24F Family Reference
Manual sections.
3: 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: Refer to the specific peripheral section or
Section 3.0 “CPU” of this data sheet 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