
7/30/2019
Cora Z7 Reference Manual [Reference.Digilentinc]
https://reference.digilentinc.com/reference/programmable-logic/cora-z7/reference-manual?_ga=2.21685883.1349070004.1564406803-1961480359.… 18/23
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 Cora Z7 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 care to prevent any shorts.
The Cora Z7 can be connected to standard Arduino and chipKIT shields to add extended functionality. Special care was taken while
designing the Cora S7 to make sure it is compatible with the majority of Arduino and chipKIT shields on the market. The shield connector
has 45 pins connected to the FPGA 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 input pairs with an input range of 0V-1.0V.
Note: The Cora Z7 is not compatible with shields that output 5V digital or analog signals. Driving pins on the Cora Z7 shield connector above 5V may cause
damage to the FPGA.
Figure 13.1 diagrams the pins found on the shield connector of the Cora Z7.
(https://reference.digilentinc.com/_media/reference/programmable-logic/cora-z7/cora-shield.png)
Figure 13.1. Shield connector pin diagram.
Pin Name
Shield Function
Cora Z7 Connection
13 Arduino/chipKIT Shield Connector