7/30/2019
Basys MX3 Reference Manual [Reference.Digilentinc]
https://reference.digilentinc.com/reference/microprocessor/basys-mx3/reference-manual?_ga=2.68739409.1349070004.1564406803-1961480359.…
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Table 20.2 summarizes the content of PMODB connector.
Table 20.2. Pmod B pinout.
Pmod pin
Schematic Label
PIC32 pin
Function
PMODB_1
JB1
RPD9/RD9
U1CTS/U2CTS/IC2/IC5/T4CK/INT2 ()/OC5
PMODB_2
JB2
RPD11/PMCS1/RD11
U1TX/U2TX/IC4/T5CK/INT4/OC4
PMODB_3
JB3
RPD10/PMCS2/RD10
U1RX/U2RX/IC3/T2CK/INT3 ()/OC3
PMODB_4
JB4
RPD8/RTCC ()/RD8
U1RTS/U2RTS/IC1/T3CK/INT1 ()/OC1/OC2
PMODB_7
JB7
SOSCO/RPC14/T1CK/RC14
INT3 ()/U5CTS/IC3/T2CK/OC3
PMODB_8
JB8
RPD0/RD0
INT1 ()/U5TX/IC1/T3CK/OC1/OC2
PMODB_9
JB9
AN24/RPD1/RD1
INT1 ()/U5RX/IC1/T3CK/OC1/OC2
PMODB_10
JB10
SOSCI/RPC13/RC13
INT4/U5RTS/IC4/T5CK/OC4
The signals going to Pmod connectors are connected to input/output pins on the PIC32 microcontroller. Review Section 1.3 Digital Inputs
and Outputs for more details regarding digital I/Os.
Instead of using the Pmod pins as regular digital input/output pins, the pins can be mapped to several peripherals, as explained in Section
1.4 Remappable pins. For example, the SPI2 interface is implemented over the PMODA pins, as explained in Section 11.2 SPI2. Also,
UART1 can be mapped over PMODB pins, as explained in Section 13.2. UART1.
The function column from the above tables lists the possible functions (available through remapping) of each pin. This information is also
availalble in the Appendix 3: Basys MX3 Pinout.
In the above tables, the highlighted pins (displayed in green color) are 5V tolerant pins. It is safe to apply 5V logic signals directly to these
pins without risk of damage to the microcontroller. All other pins support 3.3V only.
Each pin has a 200-ohm series resistor and an ESD protection diode. The series resistor provides short circuit protection to prevent
damaging the I/O block in the microcontroller if the pin is inadvertently shorted to VDD or GND (), or two outputs are shorted together.
The ESD protection diode protects the I/O block from damage due to electro-static discharge.
Although ESD protection is provided between the connector pins and the microcontroller pins, ESD safe handling procedures should be
followed when handling the circuit board. The pins on the microcontroller and other circuits on the board are exposed and can be damaged
through ESD when handling the board.
Digilent Pmods can either be plugged directly into the connectors on the Basys MX3 or attached via cables. Digilent has a variety of Pmod
cables available.
You can read more details about the Digilent Pmod Interface Specification from the most recent specification document, available on the
Digilent Pmod Wiki.
The Basys MX3 board provides a 2×15 Debug Header, exposing some pins that allow key onboard peripheral signals to be visualized with
an oscilloscope or logic analyzer.
21. Analog Discovery Debug Header
