Internal Error: Sub-system: CIO, File: /quartus/periph/cio/cio_base.cpp, Line: 1110

Description

Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 21.1 and earlier, you may see this internal error if any of the IO_STANDARD assignment settings are entered incorrectly in the .qsf (Quartus Settings File).

This may occur when assignments have been manually added to the .qsf.

Resolution

To avoid this internal error, ensure that all assignments in the .qsf are entered correctly.

You can do this by adding them via the assignment editor.

This problem is fixed starting with the Intel® Quartus® Prime Pro Edition Software version 21.3.