Clocking on EP3C16 chips?

[Altera_Forum]

I'd built a prototype of a design using the 25K LE Cyclone III chip (EP3C25...) it was working well and since we'd fit into the 16K chip we decided to migrate the design to that one before going into larger production. (The 25K LE was the only one available in the summer when we were prototyping) 

 My issue is that the chip doesn't seem to be seeing the 50 Mhz oscillator that I'm clocking it with. I can scope it and see 50 Mhz going toward the pin (we're using a UBGA so I can't access the ball itself). However, when I wire that clock input (pin A11) to anything internally it doesn't seem to see the signal.  I tried routing it to a simple counter attached to some LEDs ... no counting  I tried using it to drive a PLL ... nothing  I even tried wiring it directly to an output that I could get a scope on ... nothing.  I've got three boards and they all test the same way so I don't think that it's a component / manufacturing issue.   I've triple checked all the power and ground pins on the FPGA ... I can load it fine with the JTAG and can toggle LEDs by directly tying them high or low in verilog ... so I think the basic FPGA is working OK ... just not the clocking.  I am using the newest SP1 for Quartus 7.2 which was necessary as 7.2 alone didn't support the EP3C16... chips.   Since this software (7.2 SP1) is brand new I'm wondering if there's a bug. Has anyone else gotten it to work for a clock signal in a 16K chip?  Thanks  V

[Altera_Forum]

Hello, 

 I'm somewhat surprized cause neither EP3C25F256 nor F324 have A11 as clock input. I knew, that EP3C25 could be clocked at least from CLK0, but probably also from other CLK inputs.  Regards,  Frank

[Altera_Forum]

Frank -  

 Thanks ... I should have clarified ... I'm using the 484 ball UBGA package of the EP3C16  V

[Altera_Forum]

--- Quote Start ---  I can scope it and see 50 Mhz going toward the pin (we're using a UBGA so I can't access the ball itself)...  I've got three boards and they all test the same way so I don't think that it's a component / manufacturing issue.  --- Quote End ---     It could be a problem with fabrication of the raw board. If you have an unpopulated board, check that you have continuity from the point you scoped on the assembled board to the pad for pin A11.