Hi,
I'm trying to build a board that will use a DDRAM PC2700 memory module connected to a Cyclone II FPGA.
It uses SSTL-2 signaling, and one thing I really don't understand is why the on-chip series resistor for SSTL-2 seems to be 50 ohms (according to
- I've also measured the series resistors of my memory module and they are about 25 ohms). I think I'm going to use SSTL-2 Class I for simplicity (btw I wonder why Class II exists ? it just uses more components and sucks more power).
Any suggestion ?
Thanks,
Sebastien