DCAN-External Loopback

Akshay Immanuel

The external loopback of the DCAN module states that the TX data at the TX pin is fed to the RX pin and is stored as the RX data. This is just the TTL signals right,not the differential signals ? The transmitted data does not go to bus right? Or does the data go onto the bus and arrive back at the RX pin??

over 9 years ago

0 Akshay Immanuel over 9 years ago

Expert 1160 points

Correction: Tx pin Data is fed to the RX of the CAN core and the Rx pin is left unconnected to the CAN core. Does the data transmitted go on to the bus?

0 Charles Tsai over 9 years ago in reply to Akshay Immanuel

TI__Guru**** 191216 points

Hi Akshay,
If you are talking about the loopback mode where the main purpose is intended for the CAN core hardware self-test functions, then this feedback is done internally inside the DCAN module. The RX pin is not really used during loopback test mode. However, the transmitted messages still can be monitored at the TX pin during loopback test mode.

0 Akshay Immanuel over 9 years ago in reply to Charles Tsai

Expert 1160 points

So the message that is being sent to the Tx will appear on the bus as well?

0 Charles Tsai over 9 years ago in reply to Akshay Immanuel

TI__Guru**** 191216 points

Hi Akshay,
Yes, it will appear on the bus if you connect the TX pin via the transceiver to the bus.

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DCAN-External Loopback