4.12. MCAN

4.12.1. Introduction

The MCAN (Controller Area Network) module implements the CAN protocol with support for CAN 2.0 A, B and FD and enables seamless communication over a CAN bus. Each MCAN module supports flexible bit rates greater than 1 Mbps and is compliant to ISO 11898-1:2015. They connect to the physical layer of the CAN network through external (for the device) transceivers. The MCAN controller is responsible for message reception, transmission and management of the communication protocol. It supports both classic CAN and CAN FD (CAN with Flexible Data-Rate) specifications allowing a higher throughput and increased payload per data frame. The classic CAN and CAN FD devices can coexist on the same network without any conflict. It also provides advanced Error detection mechanisms to ensure reliable communication.

4.12.2. Features Supported

  • Conforms with CAN Protocol 2.0 A, B and ISO 11898-1:2015

  • Full CAN FD support (up to 64 data bytes)

  • Up to 32 dedicated Transmit Buffers

  • Configurable Transmit FIFO, up to 32 elements

  • Configurable Transmit Queue, up to 32 elements

  • Configurable Transmit Event FIFO, up to 32 elements

  • Up to 64 dedicated Receive Buffers

  • Two configurable Receive FIFOs, up to 64 elements each

  • Up to 128 filter elements

  • Internal Loopback mode for self-test

  • Maskable interrupts, two interrupt lines

  • Timestamp Counter

4.12.3. Test Setup

4.12.3.1. Internal Loopback

No Setup required

4.12.3.2. External Loopback

  1. The GESI daughtercard is to be connected to J51 and J46 Expansion connectors on the board.

  2. Connect MCAN instances using jumper wires.

  3. For MCU1_0, MCU_MCAN0 and MCU_MCAN1 transceivers should be connected. These are J30 and J31 on the CPB.

../_images/J721E_J7200_J721S2_External_MCU1.png

  1. For MCU2_1, MAIN_MCAN4 and MAIN_MCAN5 should be connected. These are J12 and J14 on the GESI board.

../_images/J721E_J7200_External_MAIN1.png

4.12.3.3. Transmitter

  1. Download PCAN-VIEW https://www.peak-system.com/PCAN-View.242.0.html?&L=1

  2. Connect PCAN module to the MCAN instance specified in the Test Cases table above.

PCAN Connections

../_images/PCAN_pins1.png

For MCU1_0

../_images/J721E_J7200_J721S2_Transmitter_MCU1.png

FOR MCU2_1

../_images/J721E_J7200_transmit_receive_MAIN1.png

  1. Connect PCAN Module in PCAN-View.

4.12.3.4. Receiver

  1. Download PCAN-VIEW https://www.peak-system.com/PCAN-View.242.0.html?&L=1

  2. Connect PCAN module to the MCAN instance specified in the Test Cases table above.

PCAN Connections

../_images/PCAN_pins1.png

For MCU1_0

../_images/J721E_J7200_J721S2_Receiver_MCU1.png

FOR MCU2_1

../_images/J721E_J7200_transmit_receive_MAIN1.png

  1. Connect PCAN Module in PCAN-View.

4.12.4. Applications

4.12.4.1. Examples

Name
Description
Supported SOCs

MCAN Unit Test application
Example comprises of various testcases to test functionality of the module using both Classic CAN and CAN FD. It supports internal loopback, receiver, transmitter and B2B modes.
J721E J721S2 J7200

MCAN EVM Loopback application
Example operates as either transmitter, receiver CAN nodes. Also, supports digital loop back mode. With 2 boards, can be used to emulate 2 node CAN network with one as transmitter and the other as receiver. It also provides an External Loopback test, where one MCAN instance is configured as transmitter and the other as receiver on the same board. In all modes, MCAN operates in CAN-FD with arbitration bitrate and data-phase bitrate set to 1 Mbps and 5 Mbps respectively.
J721E J7200 J721S2 J784S4

4.12.4.2. Test Cases

Application
Test Cases
Description
SOCs
Instances used

MCAN EVM Loopback Application
Transmitter Test
Sends 15 messages with varying payloads between 1 byte to 64 butes.
J721E, J7200, J721S2, J784S4
MCU1_0: MCU_MCAN0 MCU2_1: MAIN_MCAN4
Receiver Test
Receives 15 messages with payload varying from 1 byte to 64 bytes.
J721E, J7200, J721S2, J784S4
MCU1_0: MCU_MCAN1 MCU2_1: MAIN_MCAN4
Internal Loopback
Sends and receives 15 messages with payload varying from 1 byte to 64 bytes.
J721E, J7200, J721S2, J784S4
MCU1_0: MCU_MCAN0 MCU2_1: MAIN_MCAN4
External Loopback
Sends and receives 15 messages with payload varying from 1 byte to 64 bytes externally from one MCAN instance to another.
J721E, J7200, J721S2, J784S4
MCU1_0: MCU_MCAN0, MCU_MCAN1 MCU2_1: MAIN_MCAN4 MAIN_MCAN5

MCAN Unit Test Application
CAN FD Mode with Bit Rate Switching ON
Sends and receives message, checks if they match, checks if Tx Event message marker matches with sent message,captures Timestamp.
J721E
MCU1_0: Default Module: MCU_MCAN0 Default Rx Module: MCU_MCAN1

MCU2_1: Default Module: MAIN_MCAN0 Default Rx Module: MAIN_MCAN1
Classic CAN Mode
Sends and receives Classic CAN message and checks if they match.
J721E, J721S2
CAN FD Mode with Bit Rate Switching OFF
Sends and receives message, checks if they match.
J721E, J721S2
External Timestamp
Sends and receives message, checks if they match, checks if Tx Event message marker matches with sent message,captures Timestamp.
J721E, J721S2
High Priority Messages
Sends and receives high priority message checks if they match.
J721E, J721S2
Internal Loopback
Sends and receives messages in internal loopback mode, checks if they match.
J721E, J721S2
Tx Mixed Config. With Buffer & FIFO
Uses both buffer and FIFO to send and receive messages, checks if they match.
J721E, J721S2
Tx Mixed Config. With Buffer & Queue
Uses both buffer and queue to send and receive messages, checks if they match.
J721E, J721S2
Throughput
Sends and Receives messages, checks if they match, measured frames per seconds should be 85% of the theoretical.
J721E
ECC Test
In case of single bit error, corrected data is transmitted. In case of double bit error, message is not transmitted.
J721E, J721S2
ECC Self(SEC) Test
In case of single bit error, corrected data is transmitted. In case of double bit error, message is not transmitted.
J721E, J721S2
ECC Self(DED) Test
In case of single bit error, corrected data is transmitted. In case of double bit error, message is not transmitted.
J721E, J721S2
DMA Events
Sends and Receives messages, checks if they match.
J721E, J721S2, J7200
Programmable Bit Rate
Sends and Receives messages, checks if they match.
J721E, J721S2
Node State Transitions
MCAN shall transition its states properly.
J721E
External Timestamp Overflow Interrupt
Core shall receive external time stamp interrupt.
J721E, J721S2
Clock Stop Request
MCAN shall ACK back clock stop request
J721E, J721S2
Time Stamp Counter Reset
Time Stamp Counter shall get reset after calling TS Reset API.
J721E, J721S2
Bus Monitoring Mode
Message over CAN network is received by MCAN but transmitter node gets ACK error.
J721E