User manual

DE2 User Manual
33
Figure 4.8. Schematic diagram of the clock circuit.
Signal Name FPGA Pin No. Description
CLOCK_27 PIN_D13 27 MHz clock input
CLOCK_50 PIN_N2 50 MHz clock input
EXT_CLOCK PIN_P26 External (SMA) clock input
Table 4.5. Pin assignments for the clock inputs.
4.5 Using the LCD Module
The LCD module has built-in fonts and can be used to display text by sending appropriate
commands to the display controller, which is called HD44780. Detailed information for using the
display is available in its datasheet, which can be found on the manufacturer's web site, and from
the Datasheet folder on the DE2 System CD-ROM. A schematic diagram of the LCD module
showing connections to the Cyclone II FPGA is given in Figure 4.9. The associated pin assignments
appear in Table 4.6.