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Using the DIO pin that is shared with external reset

We have a TS-7600 mated to a custom IO board. The IO board is using DIO9 as an input pin. However, that pin is also the external reset. The IO board is pulling the pin low which means the TS-7600 is constantly reset.

I originally thought that the effect of the "tshwctl --resetswitchoff" command was persistent across power cycles. Then I could run the command without the IO board attached and then reattach it and use the DIO9 pin. But I tested it and it seems like "tshwctl --resetswitchoff" only works until I cycle power.

1. Can you confirm that "tshwctl --resetswitchoff" only works until a power cycle. Is there any way to make its effect persistent?

2. Do you have any suggestions for using DIO9 as an input?

Thank you.

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I received a helpful email from Kris Bahnsen. He told me that the External Reset is disabled at startup. However, the state of External Reset is used to control the output destination for the console data. The External Reset can be disabled through the config file in Initramfs.

This is the steps I took to disable External Reset:

1. Removed the SD card from the TS-7600.

2. Plugged SD card into a Linux machine.

3. Open the SD card contents. There will be a folder named "ts".

4. In the "ts" folder there is a file named "config". Open the "config" file for editing.

5. Find the line CFG_RESETSW_EN=“0”. Mine was commented out with a "#" at the beginning of the line. Delete the "#" at the beginning of the line. Save the file.

6. Replace the SD card in the TS-7600.

The External Reset is now disabled. My serial console is still working even though the External Reset pin is pulled low during startup. But that may not be the case for all devices. 

Thank you Kris.

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