Digilent 410-269P-KIT - Manual (Page 4)

chipKIT Cmod™ Reference Manual
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Page 4 of 11
5V devices will recognize this voltage as a logic high input, and some won’t. Many 5V logic devices will work
reliably with 3.3V inputs. Please check the datasheet for the 5V components you are using to ensure that 3.3V will
satisfy the logic high conditions for the components.
Some of the digital I/O pins on the PIC32 microcontroller are 5V tolerant. The analog capable I/O pins are not 5V
tolerant. The following pins are 5V tolerant: 4-11, 14-15, 27, 31, and 33-38. The other pins are not 5V tolerant and
5V signals should not be applied to those pins. All I/O pins have a 200 ohm resistor in series between the
microcontroller pin and the connector pins to provide short circuit protection. These resistors will limit the output
drive strength of the pins to approximately +/- 2mA.
Pmod TM Connectors
The chipKIT Cmod has two connectors for connecting Digilent Pmod peripheral modules. The Pmod connectors,
labeled J1 and J2, are 2x6, female pin header connectors.
The Pmod connectors on the chipKIT Cmod are both twelve-pin connectors. The connectors use standard pin
headers with 100-mil spaced pins. The twelve-pin connectors have the pins in a 2x6 configuration.
The twelve-pin connectors provide eight I/O signals, two 3.3V power pins, and two ground pins. The twelve-pin
connectors have the signals arranged so that one twelve-pin connector is equivalent to two of the six-pin
connectors. Pins 1–4 and 7–10 are the signal pins, pins 5 and 11 are the ground pins, and pins 6 and 12 are the
power supply pins.
The pin numbering that Digilent uses on the twelve-pin Pmod connectors is non-standard.
The upper row of pins are numbered 1–6, right to left (when viewed from the end of the connector), and the lower
row of pins are numbered 7–12, right to left. This is in keeping with the convention that the upper and lower rows
of pins can be considered to be two six-pin connectors stacked.
It is important to note that the Pmod connectors on the chipKIT Cmod are rotated 180 degrees in relation to each
other. Pin 1 of each Pmod connector is marked on the board. When viewing the top of the board, pin 1 of Pmod
connector J2 is the upper right pin, and pin 7 is immediately below it. For Pmod connector J1, pin 1 is in the lower
left corner and pin 7 is immediately above it. Connecting peripheral modules incorrectly could result in damaging
the peripheral module or the chipKIT Cmod.
See the attached pinout tables for more information about connecting peripheral modules and other devices to
the chipKIT Cmod. These tables describe the mapping between pins on the PIC32MX150F128D microcontroller and
the pins on the connectors.
Input/Output Connections
The chipKIT Cmod board provides 33 of the I/O pins from the PIC32MX150F128D microcontroller to pins on the DIP
connector.
The chipKIT Cmod and the MPIDE system uses logical pin numbers to identify digital I/O pins. All digital I/O pins
share their numbering with their DIP connector pin. Valid pin numbers on the chipKIT Cmod are 4-8, 10-27, and 29-
38. Pin numbers 1-3 and 39-40 refer to pins connected to power buses on the board and are not available for use
as I/O. Pin 9 can be used to reset the PIC32 microcontroller and pin 28 is unconnected. In addition, several of these
I/O pins share functionality with other devices on the board. See the attached pinout tables for more information.