如何测量DDR3的VOH（DC）参数

简短的回答是为您的示波器购买U7231A DDR3 Compliance SW。
如果您愿意，您还可以获得并使用该SW的免费14天许可证。我们使用的算法摘自该SW的手册：1获取并分割获取信号的读写突发。
找到第一个有效的READ突发.3找到所有有效的正脉冲。
有效正脉冲在有效上升沿的VREF交叉处开始，在随后的有效下降沿处以VREF交叉结束.4放大第一个有效正脉冲并执行VTOP测量。
将VTOP测量结果作为VOH（DC）值.5使用在突发中找到的其余有效正脉冲继续上一步.6确定测量的VOH（DC）组的最差结果。秘密是
找到VTOP，这在“示波器”手册中有所介绍。
我们使用的算法根据信号的形状而变化，我们如何做到这一点是范围内“秘密酱”的一部分.Al



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  The short answer is to buy the U7231A DDR3 Compliance SW for your scope. You could also get and use a free 14 day license for that SW, if you wish.

The algorithm that we use, excerpted from the manual for that SW is:
1 Acquire and split read and write burst of the acquired signal.
2 Take the first valid READ burst found.
3 Find all valid positive pulses. A valid positive pulse starts at VREF crossing at valid rising edge and ends at VREF crossing at the following valid falling edge.
4 Zoom in on the first valid positive pulse and perform VTOP measurement. Take the VTOP measurement result as VOH(DC) value.
5 Continue the previous step with the rest of the valid positive pulses that were found in the burst.
6 Determine the worst result from the set of VOH(DC) measured.

The secret is finding VTOP, which is covered in the Oscilloscope manual. The algorithm that we use changes depending on the shape of the signal, and how we do that is part of the 'secret sauce' in the scope.

Al

谢谢Al，知道VTOP是根本用途。
在范围的帮助中有一个衡量VTOP的指南。
非常感谢。
伊



     以下为原文

  Thanks Al,

It's use-full to know the VTOP is the root. There is a guideline to measure VTOP in scope's help. Thanks very much.

Huy