Quartus 16.1: Seven no_clock buried registers in cyclonev_jtag — timing model clarification

I would like clarification on seven buried registers reported as having no clock in the cyclonev_jtag timing model.

Environment:

• Quartus Prime 16.1 Standard Edition, Build 196.
• Device: 5CSXFC6D6F31C6.
• Board: Terasic DE10-Standard.
• The design includes a generated JTAG-to-Avalon Master and SLD hub.

After running create_timing_netlist, read_sdc, and update_timing_netlist, check_timing reports these seven nodes under “No Clock”:

• altera_internal_jtag~FF_36
• altera_internal_jtag~FF_38
• altera_internal_jtag~FF_39
• altera_internal_jtag~FF_32
• altera_internal_jtag~FF_33
• altera_internal_jtag~FF_5
• altera_internal_jtag~FF_1

The reported reason is:
“No clock feeds this register's clock port.”

Tcl queries confirm that all seven nodes belong to cell altera_internal_jtag, with WYSIWYG type cyclonev_jtag. This cell contains 30 buried registers: 23 have clock_edges, while the seven listed above do not.

The following direct arcs were identified:

• FF_36 → tmsutap
• FF_38 → tckutap
• FF_39 → tdiutap
• FF_32 and FF_33 → tdo
• tdi → FF_5
• tms → FF_1

For comparison, the same atom also contains these arcs:

• tck → FF_4, and tdi → FF_4
• tck → FF_0, and tms → FF_0

All pin names above belong to altera_internal_jtag. The altera_reserved_tck clock is already defined by the generated SLD constraints.

Could you please clarify:

1. What functions do these seven buried nodes represent in the timing model?
2. Is this a known behavior or limitation of the Cyclone V JTAG timing model in Quartus 16.1?
3. Are additional constraints required? If timing exceptions are appropriate, please provide the supported syntax, exact scope, and applicable documentation.
4. If this is a tool issue, is there a patch or a later version that resolves it?

I have not added clocks directly to these buried registers or applied false-path exceptions to suppress the diagnostics.

The attached console transcript contains the queries and results. It also includes some initial Tcl query errors, followed by the corrected commands and successful results. These query errors are separate from the no_clock diagnostics.

Thank you for your assistance.