Motorola MPC564EVB, User Manual

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MPC564EVB User’s Manual 1-13
Communication Ports
The CAN_A channel transceiver is provided by the Power Oak (PC33394). This transceiver has
software selectable options via the QSPI 0 channel which may communicate with the Power Oak
device. See the PC33394 data sheet for details. A 4.7K ohm pull-up is provided on the CAN_A
TX signal. Options S4 and S5 are provided near the Power Oak device to provide both MPC564
CAN_A and CAN_B channels for messaging on the Power Oak transceiver. If S4 and S5 are
connected, the B_RX option from the CAN_B port must be open.
B_RX Option Jumper
This option jumper enables the receive connection from the CAN_B port transceiver to the
MPC564 CAN B RX channel. The option allows the isolation of the CAN_B port transceiver RX
signal so that the user may use a different connection or transceiver for the MPC564 CAN B port.
C_RX and C_TX Option Jumpers
These options enable the CAN_C port transceiver RX and TX signals to be placed on the MPC564
MGPIO port CAN C signals. The CAN C operation on the MPC564 MGPIO port must be enabled
in software, see example source code. The MPC564 MGPIO Port bits 11 and 12 are effected along
with the MPC564EVB MIOS Port pins 30 and 31 respectfully.
B_EN and C_EN Option Pads, CN1 and CN2 Option Cut-Aways
These options provide access to the output enable and slew rate control of the respective CAN
transceiver. By default the transceivers are set to provide minimum slew rate (fast edge) and to be
constantly enabled for output. The configuration of the transceivers maybe modified for slew rate
or output control or both. Signaling CAN bus slew rate can be modified by increasing the value of
R66 and R67 for CAN_B and CAN_C respectfully. Opening the CN1 and CN2 away options for
CAN_B and CAN_C respectfully allows a MPC564 I/O port to be applied to the B_EN and C_EN
option pads to provide output control. A high level on the B_EN or C_EN would disable the
respective CAN transceiver output. See the PCA82C250 data sheet on the support CD for
additional information.
CAN_A, CAN_B, and CAN_C Port Connectors
These ports provide the CAN transceiver input and output connection to the CAN bus. No bias or
termination for the CAN bus is provided on the MPC564EVB board. If required the user must
install these components in the proto area or elsewhere on the CAN bus. Following are the pin
connections for the ports:
Pin 1 = CAN-Hi level signal
Pin 2 = CAN-Lo level signal
Pin 3 = Ground or common (this is required for proper return path on CAN bus)
Pin 4 = +5V supply for remote use or bias of CAN bus.
CAN_A, CAN_B, and CAN_C Port Termination Options
The RA1-3, RB1-3, and RC1-3 option locations provide the respective CAN A, B, or C port with
the ability to add bias and/or termination resistance. RA1, RB1, and RC1 locations provide low
bias (to ground) on the respective CAN Port CAN Hi signal. RA3, RB3, and RC3 locations provide
high bias (to +5V) on the respective CAN Port CAN Low signal. RA2, RB2, and RC2 locations
provide termination between the respective CAN Port CAN Hi and CAN Low signals.