ALT2GXB on CYCLONE IV GX

Hi,

Your post does not state what is the result you get, and what you'd expect. Also you do not describe your setup detailed enough.

Anyway, I had a strange GX problem with Cyclone IV GX.

I instantiated an RX-only GX unit. I did follow the reset sequence recommendation, but could not see freqlocked signal to activate.

Finally I found out that if I instantiate TXRX GX and do not use TX path at all, the freqlocked signal behaved as documented.

If I remember correctly, Altera documentation says that diff-clk is mandatory if using GX blocks. You could probably tie one pin to ground through capacitor, or tie it to a voltage which is middle of input voltage swing. But the jitter performance might suffer.

If you connect the negative pin to ground, you can not configure the input *** diff (the positive input can never have voltage smaller than negative input).

BR, -Topi