Embedded SFL not working

Hello,

I finally tried to throw light on a Serial Flash Loader issue, I experienced since long. I'm rather surprized, that Altera support seems to have never heard of a similar problem. Thus I wanted to ask, if no one saw it before?

The setup is very simple, I have a design with an embedded SFL instance. It's able to program AS configuration memory through JTAG during user mode, the same way as the factory provided SFL images do. Don't need to discuss the purpose of embedding SFL into the design in this place.

When I include another JTAG function as Source&Probe or SignalTap in the design, SFL operation fails with error: can't recognize silicon id. I see, that the AS chip select isn't operated during programming attempt, while DCLK and ASDO are still working.

To anticipate a possible suggestion, the problem seems not to be related to dual-purpose pin settings in Device Options, particularly, it doesn't help to set all pins to regular user I/O, as recommended for the Nios EPCS controller.

The problem is also different from an error no sfl ip in the design.

The problem has been found with Cyclone II and Cyclone III, and is present at least since Quartus V7.1.

Best regards,

Frank