Data Sheet

PYNQ-Z1 Board Reference Manual

Other product and company names mentioned may be trademarks of their respective owners.

Page 21 of 25

Digilent produces a large collection of Pmod accessory boards that can attach to the Pmod expansion connectors

to add ready-made functions like A/D’s, D/A’s, motor drivers, sensors, and other functions.

Each Pmod port found on Digilent FPGA boards falls into one of four categories: standard, MIO connected, XADC,

or high-speed. The PYNQ-Z1 has two Pmod ports, both of which are the high-speed type. The following section

describes the high-speed type of Pmod port.

16.1 High-Speed Pmods

The High-speed Pmods have their data signals routed as impedance matched differential pairs for maximum

switching speeds. They have pads for loading resistors for added protection, but the PYNQ-Z1 ships with these

loaded as 0-Ohm shunts. With the series resistors shunted, these Pmods offer no protection against short circuits,

but allow for much faster switching speeds. The signals are paired to the adjacent signals in the same row: pins 1

and 2, pins 3 and 4, pins 7 and 8, and pins 9 and 10.

Traces are routed 100 ohm (+/- 10%) differential.

If pins on this port are used as single-ended signals, coupled pairs may exhibit crosstalk. In applications where this

is a concern, one of the signals should be grounded (drive it low from the FPGA) and use its pair for the signal-

ended signal.

Since the High-Speed Pmods have 0-ohm shunts instead of protection resistors, the operator must take precaution

to ensure that they do not cause any shorts.

17 Arduino/chipKIT Shield Connector

The PYNQ-Z1 can be connected to standard Arduino and chipKIT shields to add extended functionality. Special care

was taken while designing the PYNQ-Z1 to make sure it is compatible with the majority of Arduino and chipKIT

shields on the market. The shield connector has 49 pins connected to the Zynq PL for general purpose Digital I/O.

Due to the flexibility of FPGAs, it is possible to use these pins for just about anything including digital read/write,

SPI connections, UART connections, I2C connections, and PWM. Six of these pins (labeled AN0-AN5) can also be

used as single-ended analog inputs with an input range of 0V-3.3V, and another six (labeled AN6-11) can be used

as differential analog inputs.

Note: The PYNQ-Z1 is not compatible with shields that output 5V digital or analog signals. Driving pins on the

PYNQ-Z1 shield connector above 5V may cause damage to the Zynq.