controller area network protocol
TRANSCRIPT
DESIGN AND IMPLIMENTATION OF CONTROLLER AREA NETWORK
PROTOCOL
Contents• Introduction
• Aim
• History
• CAN Principle
• Block diagram
• Transmitter
• Receiver
• Buffer
• Software and hardware required
• Results
• Advantages
• Applications
• Conclusion
Introduction• The Controller Area Network (CAN) is a serial communication protocol,
which efficiently supports distributed real time control with high level of
security.
• The CAN protocol is an ISO standard (ISO 11898), which includes a
physical layer and a data-link layer of the OSI model.
• Of these two layers, Data link layer is the only layer, which can be
designed and implemented using VLSI technology.
• It can transmit from 0 to 8 bytes of information.
• The maximum data rate is 1 Mbs
Aim
• To understand and develop the architecture of Controller Area Network
which is used in data link layer of the OSI model and to simulate and
synthesize it at its functional level.
History
• In February of 1986, Robeggrt Bosch GmbH introduced the serial bus
system Controller Area Network (CAN) at the Society of Automotive
Engineers (SAE) congress.
• It was introduced as ‘Automotive Serial Controller Area Network’.
• Later Uwe Kiencke, Siegfried Dais and Martin Litschel introduced the
multi-master network protocol.
CAN Principle• Data messages transmitted from any node on a CAN bus do not contain
addresses of either the transmitting node, or of any intended receiving
node. Instead, an identifier that is unique throughout the network labels
the content of the message.
• All other nodes on the network receive the message and each performs
an acceptance test on the identifier to determine if the message, and thus
its content, is relevant to that particular node.
• If the message is relevant, it will be processed; otherwise it is ignored
Block diagram
Transmitter• It has 7 states they are:1. DLC state2. Packet state3. Shift state4. CRC state5. Bit stuffing state6. Status state7. Transmission state
Transmitter state diagram
Transmitter control unit Data Length Counter
Mixer
serial
Parallel to serial CRC Generator Bit stuffing
Status register Data transmission
Receiver
• It has seven states they are
1.shift state2.de-stuffing state3.status state4.serial shift state5.CRC state6.Error message state7.FIFO state
Receiver state diagram
Reciever control unit Serial to parallel
Destuffing
Status registerParallel to serial
CRC Checker Error management logic
Buffer
• Transmit buffer and Receive buffers acts as interface to the micro
controller and the respective blocks (transmitter and receiver
respectively).
• Transmit buffer consists of two types of data namely arbitration of the
channel and user information, it takes the input from the micro
controller.
• Receive buffer consists of the user information and its output will be
taken by micro controller.
Software and Hardware required
• Software:
Xilinx ISE 14.7
• Hardware:
FPGA(SPARTAN-6)
Simulation results
• Simulation output for CAN top module
• Simulation output for Receiver
• Simulation output for transmitter
FPGA output• FPGA output for receiver
• FPGA output for transmiter
Advantages
• Low-cost, lightweight network
• Broadcast communication
• Priority
• Error capabilities
Applications
• Can was first created for automotive use, so its most common
application is in-vehicle electronic networking.
• Railway applications such as streetcars, trams, undergrounds and long-
distance trains incorporate can.
• You can find can on different levels of the multiple networks.
• Can also has applications in aircraft with flight-state sensors, navigation
systems, and research pcs in the cockpit.
Conclusion
• All architectures are developed using Behavioral modeling in VHDL and
the functionality check for each block is performed successfully.
• The entire module in the architecture has been synthesized and
implemented using XILINX ISE 14.7 software.
• The required bitmap file used for JTAG programming of the device is
obtained successfully.