RS-232 Serial Port

The DE2 board uses the MAX232 transceiver chip and a 9-pin D-SUB connector for RS-232 communications. For detailed information on how to use the transceiver refer to the datasheet. Figure 1 shows the related schematics, and Table 1 lists the Cyclone II FPGA pin assignments.

Figure 1. MAX232 (RS-232) chip schematic.

Table 1. RS-232 UART signal assignments

Signal NameDescription
UART_TXD UART Transmitter

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.


   MAX232 Dual EIA-232 Driver/Receiver, datasheet

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

Maintained by John Loomis, last updated 18 April 2007