Embedian SMARC-iMX8MM, User Manual

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Embedian, Inc.
80
SMARC-iMX8MM Computer on Module User’s Manual
v. 1.2
2.1.16.3 SPI to CAN Bridge Signals Data Flow
The path from Mrcrochip MCP2515T to the golden finger edge
connector is show in the following table.
Microchip
MCP2515T
Golden Finger Edge
Connector
Net Names Note
Pin Pin Name Pin# Pin Name
CAN0 Bus
19 TXCAN P143 CAN0_TX CAN0_TX CAN0 Transmit
output
20 RXCAN P144 CAN0_RX CAN0_RX CAN0 Receive input
CAN1 Bus
19 TXCAN P145 CAN1_TX CAN1_TX CAN1 Transmit
output
20 RXCAN P146 CAN1_RX CAN1_RX CAN1 Receive input
By SMARC hardware specification, CAN0 bus error condition signaling
should be supported on the Module GPIO8 ( P116 ) pin. This is an active low
input to the Module from the CAN bus transceiver. CAN1 bus error condition
signaling should be supported on the Module GPIO9 ( P117 ) pin. This is an
active low input to the Module from the CAN bus transceiver
A CAN transceiver on carrier is necessary to adapt the signals from SMARC
golden finger edge connector, which is TTL levels, to the physical layer used.
Because the CAN bus system is typically used to connect multiple systems
and is often run over very long distances, both power supply and signal path
must be electrically isolated to meet a certain isolation level. Users can refer
the “ SMARC Carrier Board Hardware Design Guide ” or CAN transceiver
application note such as TI ISO1050 for more details.