RS-232 Serial Communications
MOTOROLA
Technical Summary
2-5
2.3 RS-232 Serial Communications
The 56F805EVM provides an RS-232 interface by the use of an RS-232 level converter,
(Analog Devices ADM3311EARS, designated as U16); refer to the RS-232 schematic
diagram in
. The RS-232 level converter transitions the SCI UART’s +3.3V
signal levels to RS-232 compatible signal levels and connects to the host’s serial port via
connector P3. Flow control is not provided, but could be implemented using uncommitted
GPIO signals. The pinout of connector P3 is listed in
. The RS-232 level
converter/transceiver can be disabled by removing the jumper at JG9.
Figure 2-2. Schematic Diagram of the RS-232 Interface
.
Table 2-1. RS-232 Serial Connector Description
P3
Pin #
Signal
Pin #
Signal
1
Jumper to 6 & 4
6
Jumper to 1 & 4
2
TXD
7
Jumper to 8
3
RXD
8
Jumper to 7
4
Jumper to 1 & 6
9
N/C
5
GND
56F805
RS-232
Level Interface
TXD0
RXD0
R1in
T1out
T1in
R1out
6
3
2
7
8
4
5
x
1
9
RS-232 DB9
P3
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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