关于protel99 信号完整性规则设定的问题

登录 · 发表于 2010-12-13 11:44

最近正在试验用protel99进行信号完整性分析工作，遇到一个问题：
PCB 图如图1，规则设定方面：flight time--falling edge:max 2ns
                                    flight time--rising edge:max 2ns
                                    slope--falling edge:max 1ns
                                    slope--falling edge:max 1ns

                                          impedance constraint: 10~300欧姆；
                                    overshoot--falling edge:max 1V
                                    overshoot--rising edge:min 1v
                                    underovershoot--falling edge:max 1v
                                    underovershoot--falling edge:max 1v

设定好后在PCB上跑DRC。出现图2的错误。
想请教  flight time/slope--falling/rising edge以及overshoot/underovershoot--falling/rising edge  这些参数与pcb上的那些东东有关？阻抗参数大家一般是怎么设定的，有什么规则没有？

登录 · 发表于 2010-12-13 11:47

图2不清楚重发

发表于 2010-12-13 11:48

还是不行，直接发文本吧

Processing Rule : Undershoot - Rising Edge (Maximum= 1.000V) (Is part of net class usb3280single )
Violation       Net NetU2_26  Actual value =  1.167V
Violation       Net NetU2_16  Actual value =  1.653V
Rule Violations :2

Processing Rule : Slope - Rising Edge (Maximum =  1.000ns) (Is part of net class usb3280single )
Violation       Net NetU2_6  Actual value =  1.828ns
Violation       Net NetU2_5  Actual value =  1.819ns
Violation       Net NetU2_4  Actual value =  1.830ns
Violation       Net NetU2_3  Actual value =  1.791ns
Violation       Net NetU2_26  Actual value =  2.944ns
Violation       Net NetU2_25  Actual value =  1.824ns
Violation       Net NetU2_24  Actual value =  1.831ns
Violation       Net NetU2_23  Actual value =  1.834ns
Violation       Net NetU2_22  Actual value =  1.808ns
Violation       Net NetU2_21  Actual value =  1.827ns
Violation       Net NetU2_20  Actual value =  1.822ns
Violation       Net NetU2_2  Actual value =  1.809ns
Violation       Net NetU2_19  Actual value =  1.810ns
Violation       Net NetU2_16  Actual value =  3.405ns
Violation       Net NetU2_15  Actual value =  1.452ns
Violation       Net NetU2_14  Actual value =  1.259ns
Violation       Net NetU2_13  Actual value =  1.249ns
Violation       Net NetU2_12  Actual value =  1.161ns
Violation       Net NetU2_11  Actual value =  1.152ns
Violation       Net NetU2_1  Actual value =  1.759ns
Rule Violations :20

Processing Rule : Flight Time - Falling Edge (Maximum= 2.000nS)
Violation       Net NetU2_6  Actual value =  5.002nS
Violation       Net NetU2_5  Actual value =  5.023nS
Violation       Net NetU2_4  Actual value =  4.964nS
Violation       Net NetU2_3  Actual value =  5.066nS
Violation       Net NetU2_26  Actual value =  4.955nS
Violation       Net NetU2_25  Actual value =  5.013nS
Violation       Net NetU2_24  Actual value =  4.924nS
Violation       Net NetU2_23  Actual value =  4.945nS
Violation       Net NetU2_22  Actual value =  4.914nS
Violation       Net NetU2_21  Actual value =  4.920nS
Violation       Net NetU2_20  Actual value =  4.916nS
Violation       Net NetU2_2  Actual value =  5.045nS
Violation       Net NetU2_19  Actual value =  4.914nS
Violation       Net NetU2_16  Actual value =  5.032nS
Violation       Net NetU2_15  Actual value =  5.034nS
Violation       Net NetU2_14  Actual value =  5.122nS
Violation       Net NetU2_13  Actual value =  5.131nS
Violation       Net NetU2_12  Actual value =  5.225nS
Violation       Net NetU2_11  Actual value =  5.237nS
Violation       Net NetU2_1  Actual value =  5.073nS
Rule Violations :20

Processing Rule : Flight Time - Rising Edge (Maximum= 2.000nS)
Violation       Net NetU2_6  Actual value =  2.411nS
Violation       Net NetU2_5  Actual value =  2.430nS
Violation       Net NetU2_4  Actual value =  2.402nS
Violation       Net NetU2_3  Actual value =  2.487nS
Violation       Net NetU2_25  Actual value =  2.420nS
Violation       Net NetU2_24  Actual value =  2.369nS
Violation       Net NetU2_23  Actual value =  2.387nS
Violation       Net NetU2_22  Actual value =  2.353nS
Violation       Net NetU2_21  Actual value =  2.364nS
Violation       Net NetU2_20  Actual value =  2.360nS
Violation       Net NetU2_2  Actual value =  2.453nS
Violation       Net NetU2_19  Actual value =  2.354nS
Violation       Net NetU2_15  Actual value =  2.362nS
Violation       Net NetU2_14  Actual value =  2.390nS
Violation       Net NetU2_13  Actual value =  2.393nS
Violation       Net NetU2_12  Actual value =  2.429nS
Violation       Net NetU2_11  Actual value =  2.434nS
Rule Violations :17

Processing Rule : Allowable Base Value (Maximum= 200.0mV)
Rule Violations :0

Processing Rule : Slope - Falling Edge (Maximum =  1.000ns) (Is part of net class usb3280single )
Violation       Net NetU2_6  Actual value =  1.236ns
Violation       Net NetU2_5  Actual value =  1.274ns
Violation       Net NetU2_4  Actual value =  1.190ns
Violation       Net NetU2_3  Actual value =  1.356ns
Violation       Net NetU2_26  Actual value =  2.307ns
Violation       Net NetU2_25  Actual value =  1.256ns
Violation       Net NetU2_24  Actual value =  1.114ns
Violation       Net NetU2_23  Actual value =  1.156ns
Violation       Net NetU2_22  Actual value =  1.077ns
Violation       Net NetU2_21  Actual value =  1.103ns
Violation       Net NetU2_20  Actual value =  1.092ns
Violation       Net NetU2_2  Actual value =  1.312ns
Violation       Net NetU2_19  Actual value =  1.078ns
Violation       Net NetU2_16  Actual value =  3.145ns
Violation       Net NetU2_15  Actual value =  1.176ns
Violation       Net NetU2_14  Actual value =  1.364ns
Violation       Net NetU2_13  Actual value =  1.385ns
Violation       Net NetU2_12  Actual value =  1.634ns
Violation       Net NetU2_11  Actual value =  1.664ns
Rule Violations :19

Processing Rule : Overshoot - Falling Edge (Maximum= 1.000V) (Is part of net class usb3280single )
Violation       Net NetU2_26  Actual value =  2.127V
Violation       Net NetU2_16  Actual value =  2.678V
Violation       Net NetU2_1  Actual value =  1.921V
Rule Violations :3

发表于 2010-12-13 11:53

我把线长度变化（最后计算出的参数有变化），加粗（没有变化）
但：问题是图1 上白色的线，和它下面的那几根线的长度差不多，但为什么算出来的数值会差那么大呢？

发表于 2010-12-13 13:07

up 一下，别沉底了

发表于 2010-12-13 16:21

怎么没有人回答啊，大家都不用这个吗？还是protel99 太低级了？

发表于 2010-12-14 08:45

up 一下，别沉底了

发表于 2010-12-14 16:34

jixu

发表于 2010-12-16 11:38

别沉底了

发表于 2010-12-22 17:00

别沉底了

发表于 2010-12-22 17:09

帮你顶下

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