RS-232 Ports
MSC711x Application Development System (MSC711xADS) Reference Manual, Rev. 1
Freescale Semiconductor
41
5.4 RS-232 Ports
Two RS-232 ports on the MSC711xADS board assist with the development of user applications and provide
convenient communication channels with a terminal or a host computer. One port connects to the MPC8272 via the
MPC8272 SCC, and the second port connects to the MSC711x processor via the MSC711x UART. The RS-232
port for the MPC8272 is one 9-pin D-Type female connector. The connector should directly connect (via a flat
cable) to any IBM-PC compatible RS-232 port. The RS-232 connection for the MSC711x is a pin connection at
point P7.
5.4.1
RS-232 to MSC711x
The RS-232 connection to the MSC711x processor occurs via a MAX3241 transceiver that generates the required
RS-232 levels using a single 3.3 V supply. The transceiver is always enabled. The RS-232 pins can be switched to
drive an expansion connector. Figure 5-3 shows the RS-232 port signals.
Figure 5-3. MSC711xADS RS-232 Serial Port Connections
5.4.2
RS-232 to MPC8272
The RS-232 to MPC8272 port connects to the SCC port on the MPC8272 device via a MAX3241 transceiver that
generates the required RS-232 levels using a single 3.3 V supply. The transceiver is always enabled. The RS-232
pins can be switched to drive an expansion connector. Figure 5-4 describes the RS-232 port signals. The directions
I, O, and I/O are relative to the MSC711xADS board. For example, I means input to the MSC711xADS.
1
2
3
4
5
6
7
8
9
GND
NC
RX
TX
NC
NC
NC
NC
NC
Tx (O) Transmit Data
Rx (I) Receive Data