
Embedian, Inc.
87
SMARC-iMX8M Computer on Module User’s Manual v.1.0
2.1.17.3 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.