T W R - 9 S 1 2 G 1 2 8
J A N U A R Y 4 , 2 0 1 1
U S E R G U I D E
11
LIN Port
The TWR-S12G128 applies the MC33661 LIN bus physical layer device (transceiver) to
support LIN communications. The PHY may be configured as a Master or Slave node on the
LIN bus. LIN connectors J9 & J10 are configured in parallel to support pass-thru signaling.
Figure 7 below details the LIN block diagram.
Figure 7: LIN Block Diagram
The LIN interface provides optional features of slew rate control, network supply, and wake up
option. Refer to the MC33661 Reference Manual for detail on PHY functionality. The following
sections detail functionality for LIN option jumpers.
LIN Enable
The LIN PHY is enabled by default. Disable the PHY by connecting the test point, TP3, to
GND.
LIN COM Input
LIN inputs RX and TX are selectable using the COM_EN option header. Refer to Figure 6
above for details on configuring this header.
LIN_PWR Option
The LIN_PWR option jumper connects pin 1 of both LIN connectors to the +V input. In Master
mode, this option may be used to power LIN slave devices. This option requires +12V be
applied at E1/E2 inputs. In Slave mode, this option allows slave device to draw power from the
LIN network. For Slave mode configuration, external power should not be applied to the target
board. LIN_PWR is enabled by installing a shunt from JP3-1 to JP3-2. Refer to Figure 8
below.
MC33661
LIN PHY
J6 / J7
JP3
MSTR
(partial)
JP3
LIN_PWR
(partial)
CT6
MC9S12G128
RXD0
TXD0
COM_EN
(partial)
