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TMS320F28379D: Problem with external mode

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Jessé Augusto
Jessé Augusto on 17 Jul 2017
Commented: Aquib Jahangir on 11 Oct 2018
Hello everyone,
I have problem to use the external mode in the board Launchpad F28379D with Simulink. I saw the similar questions, but I haven't found an answer.
I'm using Matlab 2017a and CCS v6. I'm using the rights configurations for the external mode but when Simulink will connect with the board it shows the following error:
The serial communication works fine with the configurations bellow, then I think that is not problem with configurations.
Any help will be much appreciated! Thanks!

Answers (2)

Johannes Schnabel
Johannes Schnabel on 23 Mar 2018
This issue is likely explained by one or both of the two points below.
1. Pins GPIO42 and GPIO43 must support SCI_A. For this board, we expect that pins GPIO42 and GPIO43 have been configured for SCI_A communication (TX and RX, respectively). Can you please confirm that this is the case?
2. The oscillator frequency must match the LaunchPad's external oscillator frequency. While the F28379D has an internal crystal that oscillates at 20MHz, the LaunchPad also has an external oscillator that runs at 10MHz. Simulink's default value is 20MHz. This setting is appropriate when working with the F28379D alone. However, this frequency value can cause problems when using external mode on a LaunchPad. Please go to Hardware Implementation -> Device details -> Clocking and change the value of "Oscillator clock (OSCCLK) frequency in MHz" from 20 to 10.
Aquib Jahangir
Aquib Jahangir on 11 Oct 2018
Dear Johannes, even I am receiving the same error as mentioned by Jesse but on working on the second point of your answer I am not able to change the value of Oscillator clock frequency as there is no option available for me in the device details section. I will attach the image as well. Can you please help me in this

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Antonin on 9 Aug 2017
Hi Jessé Augusto,
You should verify that your serial over USB is configured properly and that you are using the right COM port. The following page will help you:
We introduced fast External Mode in R2016b which provides better serial streaming capabilities while running External Mode on TI C2000 devices.
We fixed one case where you would face the problem that you describe in an early release of the support package. Make sure to update your support package to the latest version by following the download link on this page: Embedded Coder Support Package for Texas Instruments C2000 Processors
Support Packages versions 16.2.5 and above fix this problem.
The only other known possible case where you would face this problem is when the COM port is used by another application (like a hyper terminal) while you run External mode. We are working on a better error mechanism for this case, in the meantime, make sure that the COM port is free to use by MATLAB prior to launching External mode simulations.
I hope it helps,
  1 Comment
K N on 20 Sep 2017
I have the same problem. Error occurred while executing External Mode MEX-file 'ext_comm': Failed to connect to the target. A time-out occurred while waiting for the connection response from the target. Possible reasons for the time-out: a) The target is not switched on. b) The target is not connected to your host machine. c) The application for the model is not running on the target. You might have clicked the Stop button. If the Run button is not dimmed, click it. Otherwise, click the Build button, which downloads and runs your application on the target. Component:Simulink | Category:Block diagram error Unable to connect to the 'TI Delfino F2833x' target for 'c28x_serial_ext'. Component:Simulink | Category:Model error

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