Using The Expansion Header - Altera DE2-70 User Manual

LCD_DATA[5]
LCD_DATA[6]
LCD_DATA[7]
LCD_RW
LCD_EN
LCD_RS
LCD_ON
LCD_BLON
Note that the current LCD modules used on DE2/DE2-70 boards do not have backlight. Therefore
the LCD_BLON signal should not be used in users' design projects.

5.6 Using the Expansion Header

The DE2-70 Board provides two 40-pin expansion headers. Each header connects directly to 36
pins of the Cyclone II FPGA, and also provides DC +5V (VCC5), DC +3.3V (VCC33), and two
GND pins. Among these 36 I/O pins, 4 pins are connected to the PLL clock input and output pins of
the FPGA allowing the expansion daughter cards to access the PLL blocks in the FPGA.
The voltage level of the I/O pins on the expansion headers can be adjusted to 3.3V, 2.5V, or 1.8V
using JP1. Because the expansion I/Os are connected to the BANK 5 of the FPGA and the VCCIO
voltage (VCCIO5) of this bank is controlled by the header JP1, users can use a jumper to select the
input voltage of VCCIO5 to 3.3V, 2.5V, and 1.8V to control the voltage level of the I/O pins. Table
5.7 lists the jumper settings of the JP1. The pin-outs of the JP1 appear in the Figure 5.10.
Finally, Figure 5.11 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 two of the pins on each header, but this circuitry is included for all
72 data pins. Table 5.8 gives the pin assignments.
JP1 Jumper Settings
Short Pins 1 and 2
Short Pins 3 and 4
Short Pins 5 and 6
Table 5.7. Voltage level setting of the expansion headers using JP1.
PIN_C2
PIN_C3
PIN_B2
PIN_F3
PIN_E2
PIN_F2 LCD Command/Data Select, 0 = Command, 1 = Data
PIN_F1
PIN_G3
Table 5.6. Pin assignments for the LCD module.
Supplied Voltage to VCCIO5
LCD Data[5]
LCD Data[6]
LCD Data[7]
LCD Read/Write Select, 0 = Write, 1 = Read
LCD Enable
LCD Power ON/OFF
LCD Back Light ON/OFF
IO Voltage of Expansion
1.8V
2.5V
3.3V
41
DE2-70 User Manual
Headers (J4/J5)
1.8V
2.5V
3.3V