TMS320F28379D: CAN Communication

Debashish Das

Part Number: TMS320F28379D
Other Parts Discussed in Thread: C2000WARE

Hi,

I have gone through the technical document (SPRUHM8I) related to CAN communication (TMS320F28379D). I need step by step procedure to initialize the CAN with example. I want to implement CAN communication between two nodes, but I didn't find any information on SPRUHM8I. I have gone through C2000 CAN communication example but I didn't get any sequence of flow. In addition I didn't understand the data flow among message RAM, IFx registers, CPU, CAN core in both transmit and receive case.

So please help me

1. To understand step by step CAN module usage.

2. Data flow among message RAM, IFx registers, CPU, CAN core in both transmit and receive case.

3. How to set up Message Identifiers between two separate CAN nodes.

over 4 years ago

0 Hareesh Janakiraman over 4 years ago

TI__Guru* 95315 points

Please download my Application report http://www.ti.com/lit/sprace5. It has many tested examples (that are part of C2000ware). The examples clearly depict the sequence of initializing the module.

Application report http://www.ti.com/lit/spracq3 depicts lot of easy to understand waveforms and also provide a tool to introduce error at a chosen bit location.

The TRM chapter explains the CAN protocol implementation in the MCU. i.e. it explains the function of registers/bits. However, it does not explain the protocol itself. For protocol information, refer to these excellent videos:

https://training.ti.com/ti-precision-labs-canlinsbc-can-and-can-fd-protocol?context=1139747-1138099-1139707-1138111

https://training.ti.com/ti-precision-labs-canlinsbc-can-and-can-fd-overview?context=1139747-1138099-1139707-1138109

https://training.ti.com/ti-precision-labs-canlinsbc-can-physical-layer?context=1139747-1138099-1139707-1138110

0 Debashish Das over 4 years ago in reply to Hareesh Janakiraman

Prodigy 40 points

Hi Janakiraman,

Thanks for your reply

The example code mentioned in sprace5 will give initialization of CAN module with respect to a particular example. But we need a generic structure of CAN module mandatory initializations step by step. In addition we want to understand the data flow (graphical flow or images) among message RAM, IFx registers, CPU, CAN core in both transmit and receive case.

Can you give some details about Arbitrary waveform generator (AWG) , USB-to-GPIB interface and USB-based CAN bus analyzer which are used for debugging CAN communication along with LabVIEW.

0 Hareesh Janakiraman over 4 years ago in reply to Debashish Das

TI__Guru* 95315 points

The example code mentioned in sprace5 will give initialization of CAN module with respect to a particular example. But we need a generic structure of CAN module mandatory initializations step by step.

The initialization sequence in terms of

Choosing the appropriate GPIO pins
Preparing the module for communication by configuring the bit-rate
Assigning MSGIDs to the needed mailboxes, configuring their direction, enabling them etc.

is pretty much identical for any scenario. It is not unique to any example. Think of the IFx registers as a "window" through which you access the Mailboxes.

Not sure why you need a AWG. SPRACQ3 uses one to introduce bit-errors in precisely chosen locations. However, you don’t need a AWG for normal CAN debug. A USB-based CAN bus analyzer is very essential; just Google "usb-can analyzer". I use the PCAN-USB Adapter made by PEAK-System Technik and quite happy with it. An oscilloscope that supports CAN triggering is vital for debug.

0 Hareesh Janakiraman over 4 years ago in reply to Hareesh Janakiraman

TI__Guru* 95315 points

Please let me know if the attached image helps.

IFX.ppt

0 Debashish Das over 4 years ago in reply to Hareesh Janakiraman

Prodigy 40 points

Hi Janakiraman,

Thanks for your reply

Please provide any documents related to CAN module initialization (CAN registers need to use) step by step.

0 Debashish Das over 4 years ago in reply to Hareesh Janakiraman

Prodigy 40 points

Thanks for reply,

I have gone through your ppt. However we need additional information to understand CAN as mentioned below

In Message transmission:

1. How the data is flowing CPU bus to CAN Transceiver ?

Ex 1: CPU bus -> Module interface --> IFx registers ----> Message Handler ---> Message RAM -----> Message Handler ----> CAN Core -----> CAN Tx pin. or

Ex 2: CPU bus -> Module interface --> IFx registers ----> Message Handler ----> CAN Core -----> CAN Tx pin.

For Message Reception case:

1. How the data is flowing CAN Transceiver to CPU bus ?

Ex 1: CAN Rx pin ----> CAN core ----> Message Handler------> Message RAM ----> Message Handler ----> IFx registers -------> Module interface----> CPU bus

Ex 1: CAN Rx pin ----> CAN core ----> Message Handler ----> IFx registers -------> Module interface----> CPU bus

0 Hareesh Janakiraman over 4 years ago in reply to Debashish Das

TI__Guru* 95315 points

Please provide any documents related to CAN module initialization (CAN registers need to use) step by step.

The initialization sequence is clearly explained in the TRM and depicted in the C2000ware examples.

However we need additional information to understand CAN as mentioned below

Please help me understand exactly what problem you are trying to solve with this information. Once you transfer all the pertinent information (ARB ID, DLC, data bytes etc) along with a request for transmit, the frame will be transmitted when the bus is free, subject to arbitration rules.

0 Debashish Das over 4 years ago in reply to Hareesh Janakiraman

Prodigy 40 points

Thanks for your reply,

Just I am trying to understand how the data is flowing (with direction wise) among message RAM, IFx registers, CPU, CAN core in both transmit and receive case with Graphical view and accordingly how to configure Dir, DIR, ARB, Control command etc.

0 Hareesh Janakiraman over 4 years ago in reply to Debashish Das

TI__Guru* 95315 points

I regret I don't have any more information than what is already there in the Datasheet/TRM.

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TMS320F28379D: CAN Communication