Altera Nios Development Board - Manual (Page 25)

Altera Corporation 1–17
December 2004 Nios Development Board Reference Manual, Cyclone Edition
Board Components
Figure 1–13. Debug Mictor Connector - J25
Serial Port
Connectors J19 & J27 are standard DB-9 serial connectors. These connectors are
typically used for communication with a host computer using a standard,
9-pin serial cable connected to (for example) a COM port. Level-shifting
buffers (U52 and U58) are used between J19 & J27 and the Cyclone device,
because the Cyclone device cannot interface to RS-232 voltage levels
directly.
The Nios development board provides two serial connectors, one labeled
Console and the other labeled Debug. Many processor systems make use
of multiple UART communication channels during prototype and debug
stages.
The Console serial port is able to transmit all RS-232 signals. Alternately,
the Cyclone design may use only the signals it needs, such as RXD and
TXD
. LEDs are connected to the RXD and TXD signals, giving a visual
indication when data is being transmitted or received. Figure 1–14 and
Figure 1–15 show the pin connections between the Console and Debug
serial connectors and the Cyclone device.