Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 22.4 and earlier, you might see this internal error during the Fitter-Plan stage when an output pin in Intel Agilex® 7 devices is stuck at VCC or GND and is using on-chip termination (OCT).
Internal Error: Sub-system: PTI, File: /quartus/tsm/pti/pti_tdb_builder.cpp, Line: 3006
FOUND ATOM WITH ZERO TIMING ARCS
ATOM_TYPE = FALCONMESA_IO_OBUF
The line number in the error message may vary depending on the Intel® Quartus® Prime Pro Edition Software version being used.
To work around this problem, choose an OCT scheme that does not use calibration. For example, change from Series 40 Ohm with Calibration to Series 40 Ohm without Calibration.
SSTL, HSTL, HSUL, and POD I/O standards use termination with calibration, even when no termination assignments are explicitly made by users.
In this case, create a termination assignment for each affected pin in the Intel® Quartus® Prime Settings File (.qsf) or Assignment Editor manually. Ensure Series <value> Ohm without Calibration is used.
This problem has been fixed starting with Intel® Quartus® Prime Pro Edition Software version 23.1.