Expansion Headers

The DE2 Board provides two 40-pin expansion headers. Each header connects directly to 36 pins on the Cyclone II FPGA, and also provides DC +5V (VCC5), DC +3.3V (VCC33), and two GND pins. Figure 1 shows the related schematics. Each pin on the expansion headers is connected to two diodes and a resistor that provide protection from high and low voltages. The figure shows the protection circuitry for only four of the pins on each header, but this circuitry is included for all 72 data pins. Table 1 gives the pin assignments.

Figure 1. Schematic diagram of the expansion headers.

Table 1. Signal assignments for the expansion headers.

Signal NameDescription
GPIO_0[35:0] GPIO Connection 0[35:0]
GPIO_1[35:0] GPIO Connection 1[35:0]

See DE2_pin_assignments.csv, a comma-delimited file that matches "standard" descriptive names to actual FPGA pin locations. This file can be directly opened in Microsoft Excel.


   DE2 User Manual, version 1.4, 2006. (pdf)

Maintained by John Loomis, last updated 28 April 2007