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allegro里仿真串扰

时间:10-02 整理:3721RD 点击:

大家好,本人正在学习Allegro里关于SI和crosstalk的仿真,遇到了下面几个困惑,不知道大家有没遇到过,有没什么好的经验,希望能共享一下啊。

1. Allegro中做crosstalk,能不能提取出多个拓扑?我没能提出来,是不是只能从report里看串扰的大小?

2.我设定了netlist,希望仿真某几条关键信号,那想知道怎样设置这些路径上的电阻、电容、电感值?PCB板上好像没有这些值,但是做仿真这些参数是非常重要的啊

3. IC的IBIS模型大家都从哪里找啊?他们的官方网站找不到怎么办呢?

4.在Allegro的串扰仿真中,可以设定信号的频率,但设定一个频率同时会赋给netlist里的所有信号,而实际情况是不同信号可能需要设定不同的频率,这个怎么实现呢?

真诚的希望大牛们能给些指点,在此先谢过啦

小编你好,很想和你学仿真!有没有好的资料发一点过来,谢谢了!

nantianyijianzj@163.com

 

啊,你太看的起我了。我才接触SI仿真两个星期,很多地方都还不清楚,呵呵。
资料嘛,我主要是看Cadence的help和一本电子工业出版社的Cadence 高速电路板设计与仿真》。

Answer your question one by one:

1. Allegro中做crosstalk,能不能提取出多个拓扑?我没能提出来,是不是只能从report里看串扰的大小?

That is right, you could not extract top into sigxp.

2.我设定了netlist,希望仿真某几条关键信号,那想知道怎样设置这些路径上的电阻、电容、电感值?PCB板上好像没有这些值,但是做仿真这些参数是非常重要的啊

What do you mean resister, capacitor, and inductor on the traces? Distribute parasitical parameter or discrete parts on the trace? As for parasitical parameter, that would be including in the transmittion line model which generated by Field Solver, when you extract the net.As for discrete parts, you could discript them through Espice model.

3. IC的IBIS模型大家都从哪里找啊?他们的官方网站找不到怎么办呢?

IBIS model is the base of SI simulation. Almost all the model you could get from the vendor. If the vendor just give you the spice model, you have to generate IBIS model yourself through spice simulation.

4.在Allegro的串扰仿真中,可以设定信号的频率,但设定一个频率同时会赋给netlist里的所有信号,而实际情况是不同信号可能需要设定不同的频率,这个怎么实现呢?

Hehe, you could use customer stumilus.

Thanks very much for your reply. But I still have some problem, one by one.

1. Allegro中做crosstalk,能不能提取出多个拓扑?我没能提出来,是不是只能从report里看串扰的大小?

That is right, you could not extract top into sigxp.

[Cindy] Now I can get multi-top through the menu of "file->Append" in Sigxp. But when I run the "simulate" command, a error dialog will appear. The content is "Cannot simulate a circuit with disconnected parts." Do you know how to solve it? Tks.


2.我设定了netlist,希望仿真某几条关键信号,那想知道怎样设置这些路径上的电阻、电容、电感值?PCB板上好像没有这些值,但是做仿真这些参数是非常重要的啊

Whatdo you mean resister, capacitor, and inductor on the traces? Distributeparasitical parameter or discrete parts on the trace? As forparasitical parameter, that would be including in the transmittion linemodel which generated by Field Solver, when you extract the net.As fordiscrete parts, you could discript them through Espice model.

[Cindy] I mean the distribute parts. Like R1=33ohm, C20=10pF. The default value is 1ohm or 1pF. I want to know how to change the value of each distribute part. Tks.

3. IC的IBIS模型大家都从哪里找啊?他们的官方网站找不到怎么办呢?

IBISmodel is the base of SI simulation. Almost all the model you could getfrom the vendor. If the vendor just give you the spice model, you haveto generate IBIS model yourself through spice simulation.

[Cindy] OK. Thank you very much. I will try it.

4.在Allegro的串扰仿真中,可以设定信号的频率,但设定一个频率同时会赋给netlist里的所有信号,而实际情况是不同信号可能需要设定不同的频率,这个怎么实现呢?

Hehe, you could use customer stumilus.

[Cindy] Perhaps I don't understand your meaning. Could you give the more detail explanation? Now I set the frequency in the "Preferences->pulse clock frequency" menu.

问得经典,顶一个,不要沉下去了

no

这几个问题对我们初学者来说太重要了!高手出来解答一下呀!

赚钱iningg。。

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