2008
Chapter-3 L19: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
1
DEVICES AND COMMUNICATION
BUSES FOR DEVICES NETWORK
Lesson-19: SERIAL BUS
COMMUNICATION PROTOCOLS
– CAN
2008
Chapter-3 L19: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
2
Serial Communication Distributed Control
Area Network (CAN) Bus
Distributed Control Area Network
example - a network of embedded
systems in automobile
2008
Chapter-3 L19: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
3
CAN Serial Bus Communication for
networking
λ CAN-bus line usually interconnects to a
CAN controller between line and host at the
node. It gives the input and gets output
between the physical and data link layers at
the host node.
λ The CAN controller has a BIU (bus
interface unit consisting of buffer and
driver), protocol controller, status-cum-
control registers, receiver-buffer and
message objects. These units connect the
host node through the host interface circuit
2008
Chapter-3 L19: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
4
Serial IO CAN bus
Serial bus controller for CAN in a
Microcontroller
CAN Device
controller
CAN Device
controller
Serial CAN bus
CAN Device
controller
CAN Device
controller
Processor of
system D
Processor of
system E
Processor of
system B
Processor of
system C
2008
Chapter-3 L19: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
5
Serial IO CAN bus in automobile
Embedded
controller
system A
CAN
controller
CAN controller
CAN
controller
CAN
controller
1 Mbps multicast, multi-master,
auto retransmission of erroneous
data, 120 Ohm line impedance
Twisted pair CAN-H and CAN-L
wires Serial IO bus
Embedded
controller
system B
(engine
controller)
Embedded
controller
system C
(antilock brake
controlle