43
43
Development Kit
43
7.5
COM Ports
By default, the four COM ports of the mosaic module are routed to the four DB9
connectors of the DevKit. Electrical levels on the BD9 conform to the RS232 standard.
RTS/CTS lines are supported only on COM2 and COM3 (the mosaic has RTS/CTS lines on
COM1 as well, but they are not routed to the DevKit). Connection to a PC is done through
a null-modem cable.
Alternatively, 3.3V TTL signals are available through four 6-pin 2.54mm pitch headers, as
shown below. The pinout is compatible with standard FTDI 6-pin SIL connectors. To route
a COM port to the 6-pin header instead of the BD9 connector, a jumper must be placed
on J800 (COM1), J801 (COM2), J804 (COM3) and/or J805 (COM4). Only those COM ports
for which the jumper is placed are routed to the 6-pin header. The other COM ports are
still routed to the DB9 connectors, using the RS232 levels.
Note that, when using the DB9 connectors, the baud rate must not be larger than
230400baud. This limitation does not apply to the TTL signals.
COM 1
COM 2
COM 3
COM 4
COM1
COM2
COM3
COM4
G
ND
R
TS (O)
NC
R
X (I)
TX
(O)
C
TS (
I)
