PIC32MX1XX Datasheet, PDF (237/320 Pages) Microchip Technology – 32-bit Microcontrollers (up to 128 KB Flash and 32 KB SRAM) with Audio and Graphics Interfaces, USB, and Advanced Analog

26.3 On-Chip Voltage Regulator
All PIC32MX1XX/2XX devices’ core and digital logic
are designed to operate at a nominal 1.8V. To simplify
system designs, most devices in the
PIC32MX1XX/2XX family incorporate an on-chip regu-
lator providing the required core logic voltage from
VDD.
A low-ESR capacitor (such as tantalum) must be
connected to the VCAP pin (see Figure 26-2). This
helps to maintain the stability of the regulator. The
recommended value for the filter capacitor is provided
in Section 29.1 “DC Characteristics”.
Note:
It is important that the low-ESR capacitor
is placed as close as possible to the VCAP
pin.
26.3.1 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. TPU is applied every time the
device resumes operation after any power-down,
including Sleep mode.
26.3.2 ON-CHIP REGULATOR AND BOR
PIC32MX1XX/2XX 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 29.1
“DC Characteristics”.
FIGURE 26-2:
CONNECTIONS FOR THE
ON-CHIP REGULATOR
3.3V⁽¹⁾
PIC32
VDD
CEFC^(2,3)
(10 μF typ)
VCAP
VSS
Note 1:
2:
3:
These are typical operating voltages. Refer to
Section 29.1 “DC Characteristics” for the full
operating ranges of VDD.
It is important that the low-ESR capacitor is
placed as close as possible to the VCAP pin.
The typical voltage on the VCAP pin is 1.8V.
PIC32MX1XX/2XX
26.4 Programming and Diagnostics
PIC32MX1XX/2XX devices provide a complete range
of programming and diagnostic features 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 26-3:
BLOCK DIAGRAM OF
PROGRAMMING,
DEBUGGING AND TRACE
PORTS
PGEC1
PGED1
PGEC4
PGED4
TDI
TDO
TCK
TMS
ICSP™
Controller
ICESEL
JTAG
Controller
JTAGEN DEBUG<1:0>
Core
© 2011-2012 Microchip Technology Inc.
Preliminary
DS61168D-page 237