Altera Nios Development Board - Manual (Page 26)

1–18 Altera Corporation
Nios Development Board Reference Manual, Stratix Edition September 2004
Serial Port Connectors
Figure 1–13. Debug Mictor Connector - J25
Serial Port
Connectors J19 and 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 Stratix device,
because the Stratix 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 Stratix 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 Stratix device.