Datasheet

chipKIT Max32 Reference Manual
www.digilentinc.com page 10 of 23
Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners.
USB: The USB OTG controller allows using
the Max32 board to implement a USB device,
USB host or USB OTG host/device. The
following pins are used by the USB interface:
Pin 27 (D+), Pin 26 (D-), Pin 25 (USBID), Pin
24 (VBUS).
Pin 24 (VBUS) can be used by a self powered
USB device to monitor the presence of bus
voltage on the USB bus. This pin on the PIC32
microcontroller is an analog input pin used by
the USB controller, and is not useable as a
user I/O pin even when not using the USB
controller.
10/100 Ethernet MAC: The Ethernet MAC
requires an external PHY to complete the
implementation of an Ethernet network port.
The Ethernet MAC constructs the digital format
of packets being sent and performs the
checking and buffering of packets being
received. The PHY provides the physical
interface and translates the digital signals used
by the MAC into the analog voltages used on
the Ethernet cable.
There are two common interfaces used
between an Ethernet MAC and the PHY: MII
and RMII. The MAC in the PIC32 supports
either interface, but the Max32 board is
designed to use the RMII interface.
The RMII Ethernet PHY interface uses the
following pins: Pin 53 (EREFCLK), Pin 49
(EMDC), Pin 48 (EMDIO), Pin 47 (ETXEN), Pin
46 (ETXD0), 45 (ETXD1), Pin 43 (ECRSDV),
Pin 42 (ERXD0), Pin 41 (ERXD1), Pin 40
(ERXERR), and Pin 7 (NRST).
CAN1, CAN2: The CAN controllers allow the
Max32 to participate in one or two CAN
(Controller Area Network) networks. CAN is a
networking standard that was developed for
use in the automotive industry and is now also
use in building automation and other industrial
applications. The CAN controllers in the PIC32
microcontroller require external CAN
transceivers to connect to the network wiring.
The CAN1 interface uses the following pins:
Pin 15 (AC1RX), Pin 14 (AC1TX). Note that
these pins are also used by UART3.
The CAN2 interface uses the following pins:
Pin 23 (AC2RX), Pin 21 (AC2TX).
The PIC32 microcontroller is designed to allow
one of two sets of pins to be used by the CAN
controllers to connect to the transceivers. The
Max32 board is designed to use the alternate
sets of pins.
Microchip Development Tool
Compatibility
In addition to being used with the MPIDE, the
Max32 board can be used as a more traditional
microcontroller development board using
Microchip Development Tools.
Unloaded connector J11 on the left side of the
board is used to connect to a Microchip
development tool, such as the PICkit™3. The
holes for JP3 are staggered so that a standard,
100mil spaced, 6-pin header can be press fit to
the board without the need to solder it in place.
Any Microchip development tool that supports
the PIC32 microcontroller family, and can be
connected via the same 6-pin interface as the
PICkit3 can be used.
Typically, a right angle male connector will be
used in J11 so that a PICkit3 can be attached
coplanar with the Max32 board. If the
connector is loaded from the top, the PICkit3
will be upright (button and LEDs visible).
Alternatively, the connector can be loaded from
the bottom. In this case, the PICkit3 will be
upside down.
If J11 is loaded from the top, the PICkit3 will
interfere with the USB connector and the
external power connector. A short six-wire
cable can be used between the PICkit3 and
the Max32. If J11 is loaded from the bottom,
the PICkit3 won’t interfere with the USB and
external power connectors.