PIC24HJXXXGPX06A Datasheet, PDF (67/294 Pages) Microchip Technology – High-Performance, 16-Bit Microcontrollers

PIC24HJXXXGPX06A/X08A/X10A
6.0 RESET
Note:
This data sheet summarizes the features
of the PIC24HJXXXGPX06A/X08A/X10A
family of devices. However, it is not
intended to be a comprehensive reference
source. To complement the information in
this data sheet, refer to the “PIC24H
Family Reference Manual”, Section 8.
“Reset” (DS70229), which is available
from the Microchip website
(www.microchip.com).
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
• WDT: Watchdog Timer Reset
• TRAPR: Trap Conflict Reset
• IOPUWR: Illegal Opcode and 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 sig-
nal 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.
Note:
Refer to the specific peripheral or CPU
section of this manual for register Reset
states.
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 POR will clear all bits, except for
the POR bit (RCON<0>), that are set. The user 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.
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.
FIGURE 6-1:
RESET SYSTEM BLOCK DIAGRAM
RESET Instruction
MCLR
Glitch Filter
WDT
Module
Sleep or Idle
Internal
Regulator
VDD
BOR
VDD Rise ^POR
Detect
SYSRST
Trap Conflict
Illegal Opcode
Uninitialized W Register
© 2009 Microchip Technology Inc.
Preliminary
DS70592A-page 65