Freescale Semiconductor MPC5675EVB, Руководство пользователя

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MPC5675EVB Users Manual Rev 2.0 July 2010
MPC5675EVB Page 8 of 29
3.5 RS232 Configuration (J5,J6,J15, J16, J23)
The EVB has a single MAX3223 RS232 transceiver device, providing RS232 signal translation for the
MCU SCI channels A and B.
Each of the two RS232 outputs from the MAX3223 device is connected to a DB9 connector, allowing
a direct RS232 connection to a PC or terminal. Connector P2A provides the RS232 level interface for
MCU SCI-A and P2B for MCU SCI-B. The pinout of these connectors is detailed below. Note that
hardware flow control is not supported on this implementation.
Figure 3-7 RS232 Physical Interface Connector
The MPC5675 SCI also provides hardware LIN master capability which is supported on the EVB via
LIN transceivers. Jumpers J17, J18, J23 and J24 are provided to isolate the MCU SCI signals from
the RS232 interface as described below. There is also a global power jumper (J15) controlling the
power to the RS232 transceiver.
Table 3-6 RS232 Control Jumpers
Jumper Position Description
J15
(SCI-PWR)
FITTED (D) Power is applied to the MAX3223 transceiver
REMOVED No power is applied to the MAX3223 transceiver
J18 (SCI-A)
2-3 MCU TXD-A is routed to MAX3223
REMOVED MCU TXD-A signal is disconnected from CAN/LIN
J17 (SCI-A)
2-3 MCU RXD-A is routed via MAX3223
REMOVED MCU RXD-A signal is disconnected from CAN/LIN
J19 (SCI-B)
2-3 MCU TXD-B is routed via MAX3223
REMOVED MCU TXD-B signal is disconnected from CAN/LIN
J20 (SCI-B)
2-3 MCU RXD-B is routed via MAX3223
REMOVED MCU RXD-B signal is disconnected from CAN/LIN
The default configuration enables SCI-A and SCI-B channels. RS232 compliant interfaces (with no
hardware flow control) are available at DB9 connector P1. If the MCU is configured such that SCI-A or
SCI-B is set as a normal I/O port, then the relevant jumpers must be removed to avoid any conflicts
occurring. If required, jumper J15 can be used to completely disable the SCI transceiver.