M 5 2 2 2 1 D E M O U S E R G U I D E
J A N U A R Y 1 8 , 2 0 0 7
16
Figure 9: COM_EN Option Header
Shunt
On
Off
CTS
▪
▪
Enabled
Disabled
RTS
▪
▪
Enabled
Disabled
RXD
▪
▪
Enabled
Disabled
TXD
▪
▪
Enabled
Disabled
COM Connector
A standard 9-pin Dsub connector provides external connections for the SCI0 port. The Dsub
shell is connected to board ground through a ferrite bead. The ferrite bead provides noise
isolation on the RS-232 connection. The DB9 connector pin-out is shown below.
Figure 10: COM Connector
4, 6
1
6
1, 4
TXD
2
7
RTS
RXD
3
8
CTS
1, 6
4
9
NC
GND
5
Female DB9 connector that interfaces to the ColdFire internal SCI1 serial
port via the RS232 transceiver.
Pins 1, 4, and 6 are connected together.
SPI Port
SPI signaling connects directly between connector J1 and the MCU. Refer to the MCF522235
RM at
www.freescale.com
for details on using the SPI interface.
IIC Port
IIC signaling connects directly between connector J1 and the MCU. Refer to the MCF522235
RM at
www.freescale.com
for details on using the IIC interface.
USB OTG
The M52221DEMO features an integrated USB On-the Go (OTG) physical layer (Phy) inter-
face. The OTG Phy connects to an MAB connector at J2. Two option headers at DPPD and
DMPD provide pull-down configuration for host mode if needed. Installing or removing both
jumpers manually controls pull-down configuration. Pull-up configuration for device mode is
integral to the MCF52221 MCU.
A high-side switch at U2 provides power to the USB bus when the board is configured for host
mode. The ILIM option header sets the output current limit. See the USB OTG Power section
above for further details.
