最近在做核心板，发现BeagleBone Black与TMDSSK3358两个开发板的DDR3上的VTT采用的方式不同。TMDSSK3358采取了使用VTT端接电阻的方式，而BeagleBone Black对VTT端接电阻取消了。我查看了Datasheet，在DDR3 and DDR3L Routing Guidelines没有太多提及VTT电阻是怎样通过布板规则进行取消的。 下面附上Datasheet的说明
Figure 7-48 provides an example DDR3 schematic with a single 16-bit DDR3 memory device that does
not have VTT termination on the address and control signals. A typical DDR3 point-to-point topology may
provide acceptable signal integrity without VTT termination. System performance should be verified by
performing signal integrity analysis using specific PCB design details before implementing this topology.
TMDSSK3358开发板可参看starterkit的原理图设计http://www.ti.com/tool/tmdssk3358
BeagleBone Black参考Beaglebone-Black的原理图设计
http://beagleboard.org/Products/BeagleBone%20Black
非常感谢！
