Uart Interface - Digilent chipKIT Pro MX7 Reference Manual

chipKIT™ Pro MX7 Board Reference Manual
#pragma config FCANIO=OFF
The MPIDE boot loader sets the configuration variables, and so no action is necessary when using the MPIDE
software system.
The pins on the PIC32MX795 microcontroller used by signals for the CAN1 controller to connect to its transceiver
are shared with two of the signals for the UART2 and SPI4 ports. Jumpers JP1 and JP2 are used to select the use of
these two signals. Place JP1 and JP2 in the CAN position for use of the CAN1 network interface. Place JP1 and JP2 in
the Pmod position for use of these signals for UART or SPI operation. These signals connect to pins 1 & 4 of Pmod
port JF. When JP1 and JP2 are in the CAN position, Pins 1 & 4 of Pmod port JF are not useable. In some cases it may
be possible to use UART2 at the same time as CAN1 as the RX and TX pins are not used by the CAN interface (only
RTS and CTS are used). When JP1 and JP2 are in the CAN position Pmod pins JF-01 and JF-04 are not connected to
the PIC32 microcontroller.
There is no standard connector for use with CAN networks. The chipKIT Pro MX7 board provides two 2x6 pin
header connectors for access to the CAN signals. Connector J9 provides access to the signals for the CAN1 network
controller, and connector J10 provides access to the signals for CAN2. Refer to the chipKIT Pro MX7 schematic,
Sheet 6, for information on the connectors and signal assignments. Digilent 6-pin or 2x6 to dual 6-pin cables can be
used to daisy chain Digilent boards together in a CAN network. A Digilent 6-Pin cable in combination with a Digilent
PmodCON1 Screw Terminal Connector module can be used to connect the chipKIT Pro MX7 board to other
network wiring configurations.
The CAN network standard requires that the network nodes at each end of a network provide 120 ohm
termination. The chipKIT Pro MX7 provides termination resistors and jumpers to enable/disable them depending
on the location of the board in the network. Jumper JP5 is used to enable/disable the termination resistor for the
CAN1 network connector, and JP7 is used to enable/disable the termination resistor for CAN2. Install a shorting
block on the jumper pins to enable the termination resistor, or remove the shorting block to disable it.
9

UART Interface

The PIC32MX795 microcontroller can provide up to six UARTs. Due to conflicting uses of many of the pins used by
the UARTs, the chipKIT Pro MX7 is designed to allow use of two of them: UART1 and UART2. The UARTs can
provide either a 2-wire or a 4-wire asynchronous serial interface. The 2-wire interface provides receive (RX) and
transmit (TX) pins. The 4-wire interface includes request-to-send (RTS), and clear-to-send (CTS), in addition to
receive and transmit.
UART1 can be accessed from Pmod port JE and UART2 can be accessed from Pmod port JF using the following pins:
 U1CTS
JE-01
 U1TX
JE-02
 U1RX
JE-03
 U1RTS
JE-04
 U2CTS
JF-01
 U2TX
JF-02
 U2RX
JF-03
 U2RTS
JF-04
Note that early versions of the Microchip PIC32MX5XX/6XX/7XX Family Data Sheet refer to UART1 as UART1A and
UART2 as UART3A.
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