[Open-graphics] DDR Vtt termination ?

[Sebastien Bourdeauducq]

Hi,

I've had a look at the board schematics from Transversal Technology, and I 
wonder why termination resistors that connect the DDRAM signal lines to a 
1.25V (Vtt) supply are not present. From what can be read in various sources, 
DDRAM uses SSTL-2 signaling which requires that resistor (see 
http://download.micron.com/pdf/presentations/dram/plat7justin.pdf p.8 for 
instance).

Is that because the PCB traces are short enough that you can get rid of that 
resistor and still get good signal integrity ?

Regards,

Sebastien