Datasheet

PIC32MX330/350/370/430/450/470
DS60001185C-page 264  2012-2013 Microchip Technology Inc.
27.3 On-Chip Voltage Regulator
All PIC32MX330/350/370/430/450/470 devices’ core
and digital logic are designed to operate at a nominal
1.8V. To simplify system designs, most devices in the
PIC32MX330/350/370/430/450/470 family incorporate
an on-chip regulator providing the required core logic
voltage from V
DD.
A low-ESR capacitor (such as tantalum) must be
connected to the V
CAP pin (see Figure 27-2). This
helps to maintain the stability of the regulator. The
recommended value for the filter capacitor is provided
in
Section 30.1 “DC Characteristics”.
27.3.1 HIGH VOLTAGE DETECT (HVD)
The HVD module monitors the core voltage at the VCAP
pin. If a voltage above the required level is detected on
V
CAP, the I/O pins are disabled and the device is held
in Reset as long as the HVD condition persists. See
parameter HV10 (V
HVD) in Tabl e 30-11 in Section 30.1
“DC Characteristics” for more information.
27.3.2 ON-CHIP REGULATOR AND POR
It takes a fixed delay for the on-chip regulator to generate
an output. During this time, designated as TPU, code
execution is disabled. T
PU is applied every time the
device resumes operation after any power-down,
including Sleep mode.
27.3.3 ON-CHIP REGULATOR AND BOR
PIC32MX330/350/370/430/450/470 devices also have
a simple brown-out capability. If the voltage supplied to
the regulator is inadequate to maintain a regulated
level, the regulator Reset circuitry will generate a
Brown-out Reset. This event is captured by the BOR
flag bit (RCON<1>). The brown-out voltage levels are
specific in
Section 30.1 “DC Characteristics”.
FIGURE 27-2: CONNECTIONS FOR THE
ON-CHIP REGULATOR
27.4 Programming and Diagnostics
PIC32MX330/350/370/430/450/470 devices provide a
complete range of programming and diagnostic fea
-
tures that can increase the flexibility of any application
using them. These features allow system designers to
include:
• Simplified field programmability using two-wire 
In-Circuit Serial Programming™ (ICSP™)
interfaces
• Debugging using ICSP
• Programming and debugging capabilities using
the EJTAG extension of JTAG
• JTAG boundary scan testing for device and board
diagnostics
PIC32 devices incorporate two programming and diag-
nostic modules, and a trace controller, that provide a
range of functions to the application developer.
FIGURE 27-3: BLOCK DIAGRAM OF
PROGRAMMING,
DEBUGGING AND TRACE
PORTS
Note: It is important that the low-ESR capacitor
is placed as close as possible to the V
CAP
pin.
VDD
VCAP
VSS
PIC32
CEFC
(2,3)
3.3V
(1)
Note 1: These are typical operating voltages. Refer to
Section 30.1 “DC Characteristics” for the full
operating ranges of V
DD.
2: It is important that the low-ESR capacitor is
placed as close as possible to the V
CAP pin.
3: The typical voltage on the V
CAP pin is 1.8V.
(10 F typ)
TDI
TDO
TCK
TMS
JTAG
Controller
ICSP™
Controller
Core
JTAGEN DEBUG<1:0>
ICESEL
PGEC1
PGED1
PGEC3
PGED3
Instruction Trace
Controller
DEBUG<1:0>
TRCLK
TRD0
TRD2
TRD3
TRD1