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Novice
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Cyclone 10 GX 3V IO Voltage

Hi community,

I have a new project based on C10 GX and I am debugging the IO problem.

 

The device is 10GX220YF672, the IO bank 2L was design to interface 3V IO.

 

I download a counter design to verify the operation, it will toggle every 200 ms.

From waveform, the high level is only 0.9V instead of 3V that I am expected.

 

What would be the problem?

If my external devices boot earlier than FPGA, will it cause this issue?

 

Please help!

 

BRs,

Johnson

 

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Employee
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Hi Johnson Lee,

 

Just want to check, have you set the IO Standard of Bank 2L to 3.0V?

 

It is not a problem for an external devices that boot earlier than FPGA if you obey the pin state as shown in the user guide:

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-10/c10gx-51003.p... (Page 273).

 

For example, LVDS I/O banks need to be tristated (Setting in Quartus) while power up and vice versa.

 

Thank You.

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Novice
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Hi YL,

Thank you for reply.

 

Yes, I did set the IO standard to 3.0V.

 

Attached is the qar file for your reference.

 

I test 2 boards with this configuration.

Both show the same status,

before config, gpio_0 is 3V, led_0 is 0.7V. After config, gpio_0 switch between 3V/ 0 V. led_0 is 0.9V/ 0V.

 

Regards,

Johnson

 

 

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Novice
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Hi YT,

I just found the clock was not operated properly, amplitude is small..

 

I will check it and see if this is the root cause!

 

Thank you!

 

Regards,

Johnson

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Novice
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Hi YT,

I have a question on the reference file.

From the table below, it means the external IO pin should be in Tristate during FPGA boot up ?

If above rule can’t be followed, what will happen to the device?

And what should I do to prevent this?

Boot external devices later than FPGA ?

Please comment.

Thank you!

Best Regards,

Johnson Lee

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Highlighted
Employee
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Hi Johnson Lee,

 

No tri-stated is needed from external pin. During FPGA power up, the pin itself will tri-state for used pin. Meanwhile for unused pin, you will need to do some setting in Quartus to enable tri-stating.

 

To do so, go to "Assignments" -> "Device" -> "Device and pin info" -> "Unused pin" -> "As input tri-stated with weak pull up"

 

Thank You

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