Specifications

Altera Corporation 23
EPXA10 Development Board Hardware Reference Manual
Serial I/O Interfaces
The development board contains two RS-232 DTE interfaces. For each, the
transceiver and any associated hardware are provided on the board.
Table 13 provides information on the devices used to implement the
RS-232 interfaces.
The transceiver requires a 3.3-V power supply. If the RS-232 input pins are
used as outputs, contention occurs because the bus transceiver is always
active. If these pins are not used as part of a design, ensure that they
remain in the high-impedance state. See Table 33 on page 45 for
information on the RS-232 DTE signals.
DTE UART Interface
The EPXA10 device includes a UART core which is directly connected to
a device to provide the RS-232 interface levels. A second UART is
provided, which is connected to 3.3-V standard EPXA10 I/O. Table 14
shows the DTE UART interface characteristics.
Table 17 lists the UART LEDs on the EPXA10 development board.
Table 13. RS-232 Interface Device Reference
Reference Part Number Manufacturer Website Address Description
U35 MAX3241 Maxim www.maxim-ic.com RS-232 DTE transceiver (connects to the
UART in the stripe using connector P1)
U38 MAX3241 Maxim www.maxim-ic.com RS-232 DTE transceiver (connects to the
soft UART in the PLD using connector P2)
Table 14. DTE UART Interface Characteristics
Features I/O Pins Voltage
UART 1 TX, RX & Control 7 3.3 V
UART 2 TX, RX & Control 7 3.3 V
Table 15. UART LEDs (Part 1 of 2)
LED Reference Description
TX_UART1 This blinks to indicate activity on the line
RX_UART1 This blinks to indicate activity on the line
TX_UART2 This blinks to indicate activity on the line